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Windows Forensics and Incident Recovery

dba599 (Mark McKinnon) submits this review of Harlan Carvey's Windows Forensics and Incident Recovery, writing "This book takes an unusual approach to computer forensics in that it deals only with live analysis of the system: the compromised computer is left powered on and everything is running. (Compare to a dead analysis, for which the computer is powered off and the hard drive's contents are then analyzed.)" Read on for the rest of McKinnon's review. Windows Forensics and Incident Recovery author Harlan Carvey pages 460 publisher Addison Wesley rating 9 reviewer Mark McKinnon ISBN 0321200985 summary Forensic analysis and incident recovery on a live Microsoft Windows is explained for the system administrator, security administrator and knowledgeable home user.

The intended audience, according to the author, is "anyone with an interest in Windows security, which includes Windows system and security administrators, consultants, incident response team members, students and even home users." The author assumes the reader is familiar with basic networking (including TCP/IP) and has some Windows administration skills. Some programming ability, though not actually required, will help out greatly with reading and understanding the many examples provided, and will let you make your own modifications (this is encouraged by the author throughout the book).

The chapter on data hiding was a real eye-opener -- it's amazing the things Microsoft has implemented as part of the operating system (and included applications) that can be used to hide things. Discovering the hidden information is talked about, as well how it is hidden. Sample topics include file attributes, alternate data streams, OLE and stenography. This is an excellent chapter with many examples; I found myself stopping after each subject to try out each of the discussed techniques.

The next chapter delves into incident preparation. Carvey addresses some of the things that administrators can do to harden their systems. He goes over the application of security policies in general, as well as intelligent assignment of file permissions. He then covers Windows File Protection and how it is implemented, and includes a perl script to implement your own file watcher. He touches briefly on patch management and anti-virus programs, then moves into monitoring. He provides quite a few scripts, and discusses other means by which you can monitor your system.

The next chapter describes tools that can be used in incident response. This chapter has quite a lot of information and took me the longest to get through, because of all the tools mentioned that I had to download and check while I was reading the book. Carvey uses a mixture of his own perl scripts and programs that can be downloaded from places like Sysinternals, Foundstone, DiamondCS and others. All of the tools used are open source (or are at least freely available). That equips the reader with a low-cost toolkit, especially important to the home user or small business owner who cannot afford to buy the commercial equivalent. Carvey does acknowledge, though, that there are quite a few commercial tools with great functionality out there.

The first part of the incident-response tools chapter deals with the collection of volatile information (processes, services, etc.); this is a vital part of live analysis. The second part deals with the collection of non-volatile information (the content of the Windows registry, file MAC times and hashes, etc.) and tools for analyzing files. Carvey also shows how some of the tools complement each other, and that there is not one almighty tool that will find all the data you need. (This is also proven by example in a later chapter when he talks about rootkits.)

The next chapter deals with developing a security methodology, and it's handled differently than in most books: the author presents the material as a series of dreams that a Windows system administrator has, showing how an individual can come up with and fine tune a methodology as incidents happen. Carvey has used this approach before in a series of articles entitled "No Stone Unturned" for SecurityFocus.com, and the creative approach appeals to me. As he moves from dream to dream, you can relate to the admin's circumstances (and mistakes), and how be and becomes better at responding to different incidents.

The next chapter talks about what to usefully look for with the tools the book has introduced. It discusses infection vectors, types of malware and rootkits, and demonstrates tools and techniques for detecting them. This is where the author makes a clear point of why you would need to run several different tools, even if some overlap. His example uses an installed rootkit; running a particular program from a previous chapter, he shows that it fails to find that anything untoward is running -- it takes another program from the same chapter to actually reveal the rootkit's presence. By cross referencing the output for both programs, you can see why you should run more then one type of analysis tool for certain areas to make sure you are not missing anything.

Finally, the author dedicates an entire chapter to his own Forensic Server Project, a two-pronged approach to live forensic analysis which uses two machines simultaneously. The first piece, the Forensic Server Module, is the listener software; this runs on a clean PC where the data will be sent from the compromised system. The other piece, called the First Responder Utility, runs several of the programs and scripts from the incident tools chapter on the compromised system . After installing everything needed for both parts of this system, I followed the author's instructions on how to run it. What a slick tool! I ran it from a couple of PCs on my home network and was able to get a lot of the information that was described in the book as well as hash values for each log file that was produced, and a general log of everything the First Responder Unit did. The whole principle of this is that when you have an incident there will be very little interaction with the compromised system, since everything is scripted to begin with.

The framework that this software constitutes is very flexible. I was able to add two new features to the Forensic Server Module and the First Responder Utility with very little code. The first addition I made was to mark all the logs as read-only on the file system after they were written from the Forensic Server module. The next addition I made was to add a perl script to scan the c:\ drive of the PC that the First Responder Utility was running on. After I made both additions, I tested everything out, and it worked great. I had my extra log files and they were all read-only. My hat goes off to the author for coming up with and including this in the book, a really nice piece of software.

You can purchase Windows Forensics and Incident Recovery from bn.com. Slashdot welcomes readers' book reviews. To see your own review here, carefully read the book review guidelines, then visit the submission page.

85 of 142 comments (clear)

  1. Your typical sharing violations by keryeski · · Score: 2, Interesting

    I can just see the "sharing violation" and "file in use" message boxes flying everywhere.

    1. Re:Your typical sharing violations by the_mad_poster · · Score: 2, Interesting

      Not only that, how do you mitigate the risk of losing deleted information to the creation of other files? I've analyzed HDD images up to 40GB and they're no party. It can take quite a bit of time to do a thorough analysis of the disk. It seems to me that you'd run the risk of losing important filesystem information or the contents of unlinked files. If some idiot runs degrag or something you could lose a good bit of critical fs data before it's stopped. Hell, everytime you launch an Office document it seems like a temp file is created. What happens when one of those overwrites deleted log information on the disk?

      --
      Alito: A vote for Alito is a punch in the eye to put that bitch back in her place!
    2. Re:Your typical sharing violations by Anonymous Coward · · Score: 3, Informative

      I can just see the "sharing violation" and "file in use" message boxes flying everywhere.

      The solution to this is to go beneath the file system. Read raw sectors from the disk and interpret FAT or NTFS yourself. You run the risk of corrupt data if a file changes while you're reading it, but it's about the only way to snag registry files and the like while the system is up and running.

      AccessData FTK Imager is capable of doing just that, and it was used for this purpose in Operation Firewall. It was also used to create disk images of mounted BestCrypt virtual drives (hint to baddies: dismount your BestCrypt virtual drives before leaving your desk).

      Disclaimer: I work for AccessData.

  2. what? by zmollusc · · Score: 3, Funny

    How do you keep a windoze box running long enough to do any forensic work on it?

    --
    They whose government reduces their essential liberties for temporary security, receive neither liberty nor security.
    1. Re:what? by Anonymous Coward · · Score: 1, Funny


      The secret is leaving it at the BIOS screen for weeks on end. It's not very useful but the machine gets wicked uptime before running MS code.

    2. Re:what? by baadfood · · Score: 3, Informative

      While that is intended no doubt to be amusing, I use a Win2K pro system to develop.

      At times I have Diablo II running in a window, DevStudiodebuggins ome app. A couple of multi megabyte spreadsheets open in OpenOffice, And of course FireFox.

      To ensure that the hardware is as unstable as possible, this runs on a dual P4, with a Matrox and an nVidia card, both dual head for a total of 4 displays - all with a mere 512Mb of RAM.

      Ironically, FireFox is the real system resource hog.

      I have to close it down every two weeks to free up some system memory. It does get restarted about once a month when my domain passwords expire - its the only damned way to ensure that some cached credentials dont lock me out of everything.

    3. Re:what? by sinan · · Score: 1

      Dual Pentium 4 ? Who makes such a mobo ???

    4. Re:what? by TykeClone · · Score: 1

      God. It's God's own motherboard.

      --
      A fine is a tax you pay for doing wrong and a tax is a fine you pay for doing all right.
    5. Re:what? by Loki_1929 · · Score: 2, Interesting

      Indeed. I use Win2k Pro at home, myself, and I must say that ECC memory has really completed the system in terms of stability. The last time it went down was about a month ago when my Antec TruePower 550 crapped out. (ugh, almost brand new!) The last time it had been rebooted prior to that was back in May when I took some hard drives out of it for use in another machine that I was putting together just for storage, and put in that damned Truepower PSU. Before that, I couldn't tell you the last time it went down for anything. I can say with confidence that it's been at least a year since I've brought it down for software issues (or from an OS crash). I couldn't put my finger on exactly when because it's been so long that I don't remember. I abuse the hell out of it and leave it running 24/7, but it never lets me down. Mozilla and Freenet are my two biggest resource hogs.

      --
      -- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
    6. Re:what? by ghjm · · Score: 1

      Then you aren't running current patches, and are vulnerable to various exploits. In order not to be vulnerable, you'll have to run Windows Update, which will require you to reboot for several of the current critical updates.

    7. Re:what? by Gentlewhisper · · Score: 2, Funny

      God. It's God's own motherboard.

      Not only goes that asshat get 10% of our money, he saves on Xeon CPUs too!

      Grrr!

    8. Re:what? by Loki_1929 · · Score: 2, Insightful

      I run patches when I do hardware maintenance. If that means I run a few months behind the latest and 'greatest' Microsoft patches, so be it. I run a router with a stateful packet filter, an application-level software firewall, an IDS, and multiple anti-virus/anti-trojan scanners. If someone manages to get into my system and stay there, they deserve it.

      --
      -- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
    9. Re:what? by Zemran · · Score: 1

      The serious side to this is that if the system is running then is what you find a result of what you are doing or what the person being investigated did. In Britain we *HAVE* to analyse dead systems as this is the only way to say we are looking at what someone else did when the system was live. You have to image the system and work with the images as it is important not to taint the evidence in any way. Any mistake will result in a lost case. One of the stupidities of Windows is that even if you mount a drive as a slave, the first thing Windows does is write to it making any work irrelevant. You have to use an OS that allows you to easily mount RO.

      --
      I love stacking my barbecues in the shed at the end of summer - you can't beat a bit of grill on grill action.
    10. Re:what? by baadfood · · Score: 1
      After a long search, during which I'd all but given up, this appeared on my local distributors price lists :-

      Gainward Geforce FX 5200 Pro/660 PCI

    11. Re:what? by baadfood · · Score: 1

      sorry. Dual XEON 1.7Ghz

    12. Re:what? by NanoGator · · Score: 1

      "Indeed. I use Win2k Pro at home, myself, and I must say that ECC memory has really completed the system in terms of stability."

      2K's pretty cool, iddn't it? I've been running Lightwave plus After Effects for several weeks straight now. Time == money is very much a fact in my line of business. I'd be the first to go running to Linux (Actually, OSX is a more likely candidate...) if Windows behaved like the anti-MS bunch imagines. Yet, rehashed BSOD jokes still get +5 funnys...

      --
      "Derp de derp."
    13. Re:what? by Loki_1929 · · Score: 1

      "then finish your story with the other things you actually HAVE to do to keep it running without "problems" like a router with a stateful packet filter, an application-level software firewall, an IDS, and multiple anti-virus/anti-trojan scanners. Yeah, I can see how good W2K is now, thanks for clearing that up."

      First of all, you pretentious and cowardly little anonymous prick, I don't have to do any of those things. I do those things because I'm paranoid about security (the smart thing to be, in my opinion), and because I don't want to deal with problems such as intrusions. Windows 2000 isn't bullet-proof 100% secure. No software ever-before written is 100% secure. My current setup isn't 100% secure. By doing the things I do, I approach 100% security. Just what OS is it that you're using that doesn't require any additional security precautions? Can it do half of what mine does? I'm the first to blast M$ for the stupid/illegal/immoral things they do, but they did a pretty decent job with Win2k.

      "is there real any technical reason you puposely avoid applying the MS patches in a timely manner"

      Three reasons. First of all, most of the patches are unnecessary, as they're not remotely exploitable on my current setup with the additional precautions I've already taken. Secondly, some patches cause major problems, like Service Pack 2 for Windows XP. I'd rather wait to hear about problems other people have had, rather than dealing with the problems myself. Thirdly, it's inconvenient. I work with computers all day long solving problems. The last damn thing I want to do when I get home at the end of the day (or early the next day) is to troubleshoot the sudden bizarre behaviors exhibited by my computer because some 0day patch from Microsoft is buggy'd all to hell. I also don't want to sit there waiting for patches to download and install, and then have to restart, and then restart all the programs I run 24/7, and then make sure everything's working as it should. When I get home, everything's up and running and waiting for me. That's how I want it.

      "then to come to /. and brag about not having to shut the system down?"

      I see; so when a Linux user laughs at how Windows users supposedly have to reboot 73 times an hour, but his computer's been up 24/7 for the past 8 years, that's "cool". When a Win2k user talks about his personal experiences with Win2k being positive, that's just silly bragging.

      "My computer only takes about 2 minutes to shut down and reboot, seems logical to me it would not disrupt you very much."

      You pretentiously assume that the world for others is identical to your perspective. Sorry to deflate your little ego, but other people actually do have different setups. Personally, between downloading and installing patches, then restarting, I'm looking at probably 3 - 5 minutes. For starting up all the things I start up, getting them all set up the way that I need them set up, and then checking to make sure they're all running properly, I'm looking at upwards of 30 minutes or more.

      --
      -- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
  3. Re:FYI by Anonymous Coward · · Score: 1, Informative

    Fuck you, spammer.

  4. Hiding Data by darth_MALL · · Score: 4, Informative

    From article:
    " Sample topics include file attributes, alternate data streams, OLE and stenography"
    Should that be Steganography?

    1. Re:Hiding Data by micromoog · · Score: 3, Funny

      You know, stenography. As in, typing the files on paper instead of in the computer. Makes them really hard to find later.

    2. Re:Hiding Data by bloodstains · · Score: 1

      "Load the first image, apply the logical and operation with the number 3 to the image, and make the image 85 times brighter, and you get the second image."

      Has anyone tried the example in the link? I'm not sure what is meant by the bolded statement in the quote from the Wikipedia article.

    3. Re:Hiding Data by kilonad · · Score: 1

      I loaded it up into IDL, and sure enough, the damn thing works. Creepy. For those of you out there with a copy of IDL handy, try the following commands:

      image = READ_PNG(Dialog_Pickfile(Filter="*.png"))
      TV, (image AND 3)*85

  5. Non-software solutions? by Limburgher · · Score: 4, Interesting

    Does the book offer any comprehensive ideas beyond tools you can download and hwo to use them? I'm really more interested in knowing where an attacker's footprints are likely to be evident, not in using some sort of footprint detector. Tools are nice, but one should have basics to fall back on when tools are unavailable or untrusted. That said, the best Windows security tool is Nero. It's great for burning Debian .isos. . .:)

    --

    You are not the customer.

  6. Here's my method by BortQ · · Score: 3, Funny
    Granted I have been called crazy, but here's my computer forensics method:

    Bring the computer to my office.

    Administer a morphine injection.

    Ask the computer about his feelings (particularly towards his parenting fab)

    Administer another morphine injection (to myself this time).

    Play some Diablo 2 on the computer.

    Upgrade computer's video card.

    Play some more Diablo 2.

    Charge computer's owner some big money.

    One last morphine injection for the road.

    Lather, rinse, repeat and you've got one hell of a business!

    --

    A Multiplayer Strategy Game for Mac OS X, Windows, and Linux
    1. Re:Here's my method by APurplePolarBear · · Score: 2, Funny

      Ok, you had me nodding my head right up until you started injecting morphine in to the road.

      You are one sick puppy, BortQ. For shame.

  7. Good read? by Baron+von+Blapp · · Score: 5, Funny
    I love books that only dish out arcane knowledge that .02% of the windows sys admin or windows security [sic] community will use once in a life time.

    Cool, I love arcane knowledge *hugs his falconry for dummies book*

    --
    "It's too bad she won't live, but then again who does?" - Gaff
  8. Live analysis. by grub · · Score: 5, Interesting


    We had an SGI IRIX system rooted a while ago. One of those obscure machines that sat in a corner running for years, rarely updated or touched. When it was discovered that the machine was taken over the person that admin'd the machine left it exactly as is but firewalled and VLAN'd the machine from touching anything outside of a test VLAN he set up.

    In February he gave us (network guys visiting his branch) a look at the machine and what he found. The machine, the root kit and the IRC bot were all left intact and running. It was pretty neat, he wrote up a lengthy port-mortem of the event.

    --
    Trolling is a art,
  9. Re:A much better book! by Baron+von+Blapp · · Score: 1

    You got the security part right ;)

    --
    "It's too bad she won't live, but then again who does?" - Gaff
  10. Re:Who needs books!? by MeerCat · · Score: 1

    I'm willing to bet that he doesn't have a hardware drive copier that supports SATA

    Really ?? How much are you willing to bet on that ??

    Hmmm, I wonder if Google will predict roulette numbers for me too ;^)

    --
    I spent a lot of money on booze, birds and fast cars. The rest I just squandered. - George Best
  11. Re:Who needs books!? by datastalker · · Score: 1

    The tool that you're probably referring to is EnCase by Guidance Software.

  12. Re:Who needs books!? by FyRE666 · · Score: 1

    Good grief! Are you serious? I think a "police budget" can stretch to *zero* dollars to install Linux and mount your super 31337 ReiserFS drive.

    The only way you've any chance of hiding your Pr0n is by using an encrypted filesystem like CryptFS, an encrypted loopback or whatever...

  13. Re:Who needs books!? by SlamMan · · Score: 1

    Because you can't pick up a SATA drive dock?

    --
    Mod point free since 2001
  14. Re:Who needs books!? by stratjakt · · Score: 2, Informative

    I'm willing to bet that he doesn't have a hardware drive copier that supports SATA. And his software doesn't recognize reiser4 or xfs.

    I'm willing to bet you're wrong. A SATA-PATA converter is 20 bucks, if thats what it takes. And even if you don't recreate the files, you can still search bit for bit for tags like "JFIF" which denote the start of a jpeg file, and then just grab the data to see what the jpeg file is of.

    Believe me, linux is not beyond the long arm of the law. When the FBI raids the big warez sites, do you think those are all windows machines? They manage to get convictions.

    --
    I don't need no instructions to know how to rock!!!!
  15. Re:Who needs books!? by towaz · · Score: 2, Informative

    i'm sure most police forensics people have a copy of dd and netcat :)

    --
    "I disapprove of what you say, but I will defend to the death your right to say it." - Voltaire
  16. Re:Who needs books!? by Anonymous Coward · · Score: 5, Informative
    I thought this post looked familiar

    If you're going to repost other people's posts, at least preserve the formatting, you lazy turd.

  17. Re:Who needs books!? by Grond_the_Hammer · · Score: 5, Informative

    1) This is no "one" tool accepted in court, many tools are accepted and it is almost always the competency of the examiner and only rarely is the tool that is ever called into question. Companies like Guidance Software (makers of Encase) would like you to think that way...

    2) Most dedicated computer forensic tools, especially those for examining hard drive images, can work with any filesystem from FAT12 to xfs on a RAID 5 set. Again, the burden falls on the examiner to know the proper tools/methods for examining these file structures.

    3) SATA drives can be copied with any dedicated hardware copier (such as Logicube's MD5 or Solitaire), but dd combined with an SATA interface will work just fine. Any memory image (RAM, IDE, SCSI, SATA, etc.) can be imaged with just dd, even over a network.

    4) "Average nerds and hackers are so far ahread of the forensics guys"...what nonsense. Computer forensic analysts are without a doubt some of the most talented people in IT period. Computer forensics is multi-discipline and analysts typically have backgrounds in engineering, programming, criminology, and languages. And why are you assuming that most computer forensics experts are in law enforcement? The best analysts are in the private sector, military, and government intelligence.

  18. Re:FYI by the_mad_poster · · Score: 3, Informative

    Or here if you'd rather not use an affiliate link and pay someone who didn't do anything more than type a few words into a search box.

    --
    Alito: A vote for Alito is a punch in the eye to put that bitch back in her place!
  19. Live "Forensics" by stew1 · · Score: 5, Interesting

    "Forensics" on a live system is a misnomer. For incident response, collecting live data on open ports, running processes, logged on users, and mounted devices is useful and sometimes necessary. Investigators should be sure to check -- gingerly -- whether any encrypted volumes are mounted.

    Generally, however, if there's any chance that the investigation could wind up in court, it's best to pull the plug (literally) and conduct a static analysis of the hard drive. You lose access to running processes and some live registry keys, but otherwise just about everything exists on the hard drive and is accessible through standard forensic tools.

    As a forensic programmer/consultant, one of the biggest problems I run into is when J. Random Sysadmin is tasked with conducting an initial investigation and ends up rampaging through the hard drive like a bull in a china shop. If you ever find yourself in this situation, stop and get the facts. There's no better way for a sysadmin to wind up in the doghouse than to ruin a legal investigation.

    Jon

    (Disclaimer: I work at Guidance Software, makers of EnCase, which is the all-in-one tool that can do all of the things mentioned in the review. But not for free...)

    1. Re:Live "Forensics" by pbranes · · Score: 3, Insightful
      I see your point, but the extreme difficuly comes when a sysadmin should determine that something needs to be handled by the information security officer and not by himself. Here's an example:

      You have an older server that has a relatively small hard drive. You get a complaint from somebody saying they can't do so and so on the server. You look on it and find that the hard drive is full. You think, oh great, somebody printed a 200mb print job again and filled up the hard drive. Well, time to reboot the server. You have just lost an enormous amount of evidence and you may never know where the pirated games, movies, and music came from.

      I am a windows/linux sysadmin and when something goes isn't working right, my first thought is not *I'VE BEEN HACKED*, no its "stupid {some software}, {some company} can't program to save their life. time to restart the service or reboot". I will agree that discovering a problem at this point is too late - you're already 0wN3d. Instead of focusing on forensics, we need to focus on proactive measures - use group policies to enforce better security policies; use ntop, nmap, snort, gfi languard, and ms baseline security analyzer to check your systems; dump your linux and windows boxes to a syslog server that notifies on any irregularities; use SUS, SMS or something similar to patch all systems quickly and efficiently. If we are more proactive, then forensics will be less of an issue.

    2. Re:Live "Forensics" by stew1 · · Score: 3, Insightful

      And that kind of an IT response (problem? reboot!) is fine, because you've got work to do after all.

      However, at the point that you discover that there's been an incident, you should note what's running (ps), what's open (netstat), who's logged on, and what drives are mounted. Document everything that you do (date/time, action, reason for action), pull the plug, and call your lawyer.

      Incident response is difficult as the scale of the "response" can vary so widely. Sometimes it's enough to run a virus scanner and reboot. Other times you may find you've been 0wn3d by international hackers conducting IP theft (I've seen it) and you need to proceed very carefully. And then there are the HR investigations...

      My main point is simply that when geeks start to tread into the area of incident response/forensics, it's important for them to know what they're doing. When you're operating in the context of traditional IT, an IT response is okay. When you're operating in the context of an investigation, a traditional IT response is typically the worst thing you can do.

      You are also very correct, though, in noting that pro-active security is where the typical sysadmin should have his/her focus. You don't want to be the sysadmin who let in the international hackers stealing all your company's intellectual property.

      Jon

    3. Re:Live "Forensics" by JackAsh · · Score: 1

      Jon,

      I find that second paragraph interesting - doesn't that directly contradict the purpose of your Encase Enterprise Edition product? (of which my security team happens to be a happy customer, btw.?) Also, isn't there a new Live Analysis feature?

      For the uninitiated, Encase is quite possibly the industry standard tool for Forensic analysis. The latest interation, Encase Enterprise Edition, allows for forensic acquisition over a live network with the installation of a 100k agent on the target machine. Ideally this agent has been predeployed to your enterprise clients which makes it so you don't corrupt data at the last moment.

      -Jack Ash

    4. Re:Live "Forensics" by stew1 · · Score: 1

      Hi Jack -

      The EEE "servlet" will not write anything to the filesystem directly. Acquisitions are made on a low-level sector-by-sector basis.

      However, running *any* program on a targetted system necessarily changes it. The operating system has to allocate memory and CPU time for the process, and on any modern system that can invoke a write to the pagefile/swap area. This is just the way life is, and for corporate investigations -- which almost never go criminal -- this is more than good enough.

      Whether an investigation is internal, civil, or criminal, it's important to know and follow forensic best practices. If you know an acquisition is going to be used in a criminal investigation, my understanding is that it is generally preferable to pull the plug and image the drive off-line. But that's only if you've got a trusted tech on-site to do the job at the time...

      Jon

    5. Re:Live "Forensics" by MoralHazard · · Score: 2, Insightful

      "Forensics" on a live system is a misnomer. For incident response, collecting live data on open ports, running processes, logged on users, and mounted devices is useful and sometimes necessary. Investigators should be sure to check -- gingerly -- whether any encrypted volumes are mounted.

      Why a "misnomer"? Forensics, in the usage of the phrase "computer forensics", is an extension of our usage of forensics to refer to the presentation of evidence in court. The word initially means "methods pertaining to proving a proposition by logical argument". It doesn't matter whether the collection of data is live or not, it's still "forensics".

      Your statements, despite your credentials, suffers from the failing of being Windows-centric (come on "registry keys"?), and (worse, still) Encase-Centric. And your advice about pulling the plug is horrifically oversimplified.

      What happens when someone's walked into your LAMPS servers through an unpatched OpenSSH vulnerability, but hasn't installed a rootkit? If you just "pull the plug", the real evidence of the intrusion goes bye-bye because none of it was written to the hard drive. You'll probably want to look at netstat, maybe take a core dump to a remote machine, and generally examine the state of the running machine. THEN, depending on the type of filesystem, you either A) pull the plug, B) issue a 'flush' and then pull the plug, or C) go through the machine's normal shutdown procedure.

      Think about it: If you just pull the plug without thinking the matter through, you stand a good change of fucking things up. Yes, many sysadmins cause problems by trying to do too much work on their own, or taking steps that actually destroy existing evidence, but that's no reason to give blanket advice that can be as shitty as it is good!

      The correct solution: train the sysadmins to be first responders, or at least train them enough to be capable of keeping their hands off the systems until qualified help arrives. Whether you have in-house incident response people or you hire an outside firm, make sure that your admins consult with them before moving on anything that could lead to a legal issue.

      Your biases are reflective of desktop experience on Windows platforms, which is a large part of forensic work, I'll grant. But it's far from all of it, and it's actually counter-productive on many non-Windows machines. For instance: are you familiar with a thing called tmpfs? It's a RAM-based filesystem for the /tmp directory (or any other mount point, potentially) that allows seamless file-and-directory semantics but that never writes anything to disk.

      Guess what? JUST ABOUT EVERY LINUX DISTRO USES TMPFS, NOWADAYS! Can you imagine how badly you would screw up investigations if you went around pulling plugs on a bunch of Linux machines, and losing the entire contents of their /tmp directories in the process? That's liable to get you in the doghouse, that's for sure!

      There's no excuse for looking like an expert but giving poor advice, even if this IS Slashdot.

    6. Re:Live "Forensics" by dexterpexter · · Score: 2, Insightful

      Commenting on the pulling the plug...

      this is generally suggested for law enforcement who respond to a crime scene for which there is a standalone running machine and a qualified computer forensic examiner is not readily available. In the "bag and tag" process, the responding cops are then told to pull the plug (literally...not from the wall, but from the machine itself) and then bag and tag the machine. This might seem odd at first, and yes things can be lost, but the key is obtaining "forensically sound" evidence which is admissible in court.

      Just as you wouldn't want the computer guy touching the dead body on the floor, you don't want the average police guy trying to do an analysis of the machine. Even if he does open a few folders and find undeniable evidence of the crime, a good crossexaminer would rip that up in court. The idea is that you allow the least amount of "tampering" as possible before the guy who knows what he is doing gets ahold of the machine.

      Now, that said, if you walk in and there is an unsaved but important-looking document sitting on the desktop, you're not going to want to pull the plug. At that point, you take pictures and then have several witnesses present to try to preserve the document by saving it to an external drive. In that case, you gotta do what you gotta do.

      However, the plug-pulling strategy, I can second, is a standard practice for first responders when a live, on-site replication of the machine is not possible. In that case, you really do have to pull the plug, bag, tag, and examine later.

      --

      *-*-*-*-*-*-*-*
      "We are Linux. Resistance is measured in Ohms."
    7. Re:Live "Forensics" by slash.dt · · Score: 1
      Can you imagine how badly you would screw up investigations if you went around pulling plugs on a bunch of Linux machines, and losing the entire contents of their /tmp directories in the process? That's liable to get you in the doghouse, that's for sure

      You know, all the time that I was reading the previous comments, when people talked about 'plugging the plug', I assumed that they meant the network connection, it didn't occur to me that they meant the power. Unless the process is stomping all over your fs, I would leave it running but incomunicado by preference. That would keep the evidence (unless the process was designed to delete itself if it lost network connectivity).

    8. Re:Live "Forensics" by JackAsh · · Score: 1

      Thanks for the response - I agree with you in that running a program does indeed change the system, but I guess the key question is whether it is better to guarantee no changes whatsoever or risk losing volatile data (which could also be very valuable in the case on an investigation into an ongoing matter, like a hack).

      We do have a forensic group on-site or near-site (quick response available). I seem to recall also that PriceWaterhouse is working with Guidance in piloting EEE as a "valid" tool for criminal investigations - I think the philosophy they are adopting is that in modern systems with 512MB and up changing 100KB of disk is preferrable to losing those 512MB...

      In any event, thanks for the response, and good job. I can definitely say that every time we've needed to work with your company it's been an absolute pleasure.

      -Jack Ash

    9. Re:Live "Forensics" by stew1 · · Score: 2, Insightful

      Windows-centric? The title of the book is *Windows* Forensics and Incident Response. I guess this is Slashdot so I should expect to be flamed for being on-topic...

      My top post isn't about EnCase.

      As others note here, standard forensic practice -- especially when you don't know what you're doing -- is to pull the plug. That's what the DOJ says, at least.

      In the example that you give, of the OpenSSH vulnerability, it's very likely that the intruder will leave filesystem artifacts. sync() runs every few seconds. Syslog keeps track of all kinds of events (not to mention shell history files!). Sure, if someone's got root they can cover their tracks completely, but we're rarely dealing with Moriarty -- usually it's Moe and his friends, Larry and Curly.

      Additionally, the distinction needs to be made between forensics and incident response. That distinction is definitely murky, but it exists. When you suspect an "incident", which is usually a code word for "exploited vulnerability", yeah, gathering live data totally makes sense, and I'd do it. Once I'd gotten my data, I'd then pull the plug. For forensic software, mildly corrupt filesystems resulting from powerloss is not a big deal. But if you think about the potential for losing artifacts that is entailed from performing a clean shutdown, you can see why abrupt power cut-off is the way to go.

      For example, tmpfs. Sure, tmpfs is a "RAM"-disk, but that memory is backed by swap. If I'm the kernel, I bet I'm going to see that a lot of the files in this 'tmpfs' are relatively unused -- swap them away! Now, consider what happens when you perform a shutdown. Processes are killed, users are logged out, daemons are signalled, runlevels are changed, etc., etc., etc. That sounds to me like a pretty invasive procedure, one that could very well involve lots of swapping. So then you lose tmpfs. As noted above, if I really cared about the live data, I'd capture it, as simply as possible, and then I'd pull the plug. So I'd run ps, netstat, maybe lsof, and ls -ls /tmpfs. And then the plug would be pulled.

      As far as getting in the doghouse, my experience has been that it's far better to be in everyone else's doghouse but have your General Counsel love you than to have everyone else love you and be in your General Counsel's doghouse. That's the key point, really: When legal gets involved, IT doesn't matter.

      cheers,

      Jon

  20. Analogy by barcodez · · Score: 1, Funny

    Windows Forensics
    crack whore at the gynecologists

    --

    ----
  21. Re:Who needs books!? by stratjakt · · Score: 1

    Only until a judge orders you to decrypt it. And then you decide whether you want to face child porn charges, or somewhat weaker child porn charges + contempt of court charges.

    If you're at the point that your hardware was siezed, you know they already have enough on you to get a warrant. The cops are just trying to make their case against you airtight, but that doesn't mean that it doesnt already float.

    --
    I don't need no instructions to know how to rock!!!!
  22. Re:Who needs books!? by Spoing · · Score: 1
    1. I'm willing to bet that he doesn't have a hardware drive copier that supports SATA.

    There are data recovery shops that probably do have the necessary equipment...though I don't see a problem with taking the drive, booting off of a CD and doing a bit copy to another drive using dd.

    In either case, I think your confidence level is a bit too high. The forensics software I've used has checksum ID strings for known files and uses that as the basis for finding the known parts. These checksum databases are available for Unix-like systems, not just Windows. Once accounted for, the remaining file space can be investigated for other data.

    1. The real problem is that the average nerds and the hackers are so far ahead of the forensics guys in terms of knowledge about modern technology and software that they can't keep up. Hackers will always have bleeding edge tools, and police budgets can't

    The average hacker vs. the average cop, no doubt you are correct. The average hacker vs. a professional data forensics expert...it all depends on how much time the forensics expert has to do the investigation.

    --
    A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
  23. Re:Who needs books!? by Otter · · Score: 1
    And if the case is too small they wont bother.

    As is always the case, the degree of security you need depends on how much effort anyone is going to put into compromising it. If you're a low-level pot dealer, you're probably right that your obscurity provides adequate secuity. On the other hand, if you're Osama bin Laden, I'm thinking they'll get your drive to someone who can read reiser partitions.

  24. MOD PARENT DOWN by pbranes · · Score: 2, Informative

    He is just spamming with his amazon account.

  25. Re:Who needs books!? by bani · · Score: 1

    "Then they use this software tool, which I forget the name of, which is the only tool that holds water in a court of law."

    No.

    It's the only tool they know how to use.

  26. Re:Who needs books!? by Anonymous Coward · · Score: 1, Informative

    EnCase (which by the way supports reiserfs), iLook and SMART are perhaps the three most common drive analysis tools. Dont discount forensics guys, perhaps your local pd might not have a lot of knowledge, but the fbi, air force and several other agencies all have labs developing and deploying technology to do digital forensics, and i doubt theyre hiring idiots.

  27. Re:FYI by micromoog · · Score: 1

    Clicking that link or modding the parent post up = making spam profitable. Friends don't let friends support spam.

  28. Re:Who needs books!? by thundergeek · · Score: 2, Informative

    That's not entirely true.

    The local Computer Investigation B. has some prety sofisticated stuff, all there software is used much the same way you described in court.

    There was a case a few years back here where a guy had some files on his linux box that were incriminating. He set a script to do 10 DOD wipes. That's writing 1's and 0's 7 times over the HD, X 10.

    The lab was able to 1:1 the drive, then recreate every file that was saved to the HD since the purchase date.

    My friend runs this lab, he said his record is 15 reformats, and still recovered data. He recently had his first SATA case, he was able to dup the drive, and, since the guy had never reformated, and was on his first linux install, he had no problems!

    Remember, the NSA can ALWAYS do it, most of the time before hackers can! They in turn hand down the info (as needed) to the FBI, CIB, and finally in the form of books, like this guy did.

    It wouldn't suprise me if SATA has been cracked from day 1 release to the public. And xfs, the same.

    My 2cents worth, take it for face value, it's all I got.

  29. Re:FYI by Anonymous Coward · · Score: 2, Funny

    Fuck you and your harmless self-interest. How dare you try to benefit from others without actually harming them. You make me sick.

  30. Re:Who needs books!? by stew1 · · Score: 2, Informative

    There are all kinds of ways to image a SATA drive. It's a non-issue. Worse comes to worst, we boot your system up in DOS and acquire it via crossover cable.

    EnCase supports Reiser3. I don't know whether Reiser4 is so radically different from Reiser3 that we can't decode the filesystem currently, but I'm sure we could roll it out the door quickly if there was a large need. We've done it for our customers before.

    We can't yet do XFS, but we could still recover quite a bit of data from unallocated. As others have noted, all you need to get an image is good old dd.

    In many respects, savvy forensics investigators are far ahead of most criminals. Police forces band together to create high tech task forces, and they tend to have plenty of budget (e.g. they have their own clean rooms for manufacturing damaged hard drive parts). With all the ways that Windows and most applications leak information, it requires an extreme amount of discipline to avoid littering your hard drive with evidentiary artifacts.

    It sounds like you do need a book.

    cheers,

    Jon

  31. Re:Who needs books!? by DnemoniX · · Score: 2, Informative

    That is why any good investigator keeps more than one tool in his kit. Personally I have a bootable windows environment that I custom build for doing work with Windows. And for a system like yours I pop out my handy bootable Linux CD. It is based off of Gentoo and has more than enough bells and whistles to handle reiser or xfs and pretty much anything else you care. If I need something more I tweak the packages and kernel and recompile. Once you have that bit for bit copy you have all the time you need to work on it. And FYI there are many many packages that "hold water" in a court of law. I will also be giving a lecture in December at a nearby university on computer forensics. Funny how arrogant attitudes like that in most cases get you busted when you think you are smarter than those doing the looking.

  32. Re:Who needs books!? by fubar1971 · · Score: 1

    but against someone using out of the ordinary stuff this guy is screwed. I've got serial ATA drives and reiser4 and xfs file systems. I'm willing to bet that he doesn't have a hardware drive copier that supports SATA. And his software doesn't recognize reiser4 or xfs. He would either need a different tool or he would have to send the drive someone higher up to be examined.

    Man, you just the exact situation I had happen last year. My Linux email server was compromised do to a vulnerabilty in squirrelmail/UW Imap. They didn't do any damage that I could find, so I just took the email server off line, and buitlt a brand new one and hardened it. Unfortunatelly, my boss had to find out, because email was down for 1 day. Since she found out, she wanted me to report it to the Feds. I relunctantly did so. 3 Feds showed up. I handed them the drive, and they made an image of it with the device that you have mentioned. They then tried to use their SW to examine it. Guess what, it only works on WINBLOWS FORMATTED DRIVES. They couldn't see any of the data. They have since stopped investigating the case.

  33. OS integrated DRM and Steath "hiding" technique by NZheretic · · Score: 4, Interesting
    Microsoft's planned Digital Right Management systems are based on the principle of locking the owner of the computer out of the ability to access sections of memory and disk space used by the DRM mediaplayer systems.

    Crackers and hackers always find ways to exploit the code to access or share protected content. There is not a DRM system that has not been cracked within months of widespread release.

    A stealth virus is one that, while active, hides the modifications it has made to files or boot records. It usually achieves this by monitoring the system functions used to read files or sectors from storage media and forging the results of calls to such functions. This means that programs that try to read infected files or sectors see the original, uninfected form instead of the actual, infected form. Thus the virus's modifications may go undetected by antivirus programs.

    OS based DRM systems can still successfully lock a user, and any program, even if is running under localsystem/root privilege, out of areas of diskspace and memory. Microsoft's Mediaplayer , Active-X ( used with some DRM protection ), Real's realplayer, and even Microsoft's and Sun's Java JVMs, have in the past had remotely exploitable vulnerabilities. Such enviable offers the malware creator the ability to hide the virus from any antivirus tool or live forensic analysis.

    The DRM encryption offers the ability for the malware to store content, and without the keys to decode the content, it is hidden from any forensic analysis.

    1. Re:OS integrated DRM and Steath "hiding" technique by Tim+C · · Score: 1

      Crackers and hackers always find ways to exploit the code to access or share protected content... The DRM encryption offers the ability for the malware to store content, and without the keys to decode the content, it is hidden from any forensic analysis.

      Make up your mind. Which is it? Can the code *always* be exploited to "access or share protected content", or can malware hide itself "from any forensic analysis"?

    2. Re:OS integrated DRM and Steath "hiding" technique by dmaxwell · · Score: 1

      I think what he is trying to say is that malware authors can use DRM "features" to make the investigator and sysadmin's job harder.

    3. Re:OS integrated DRM and Steath "hiding" technique by Deagol · · Score: 1
      There is not a DRM system that has not been cracked within months of widespread release.

      Somebody cracked the DRM system for DVD-Audio? I'd love to know where that utility is.

      Or does DVD-Audio's encryption system not count as true DRM?

      Serious question. Last time I checked (and I search every couple of months), nobody had cracked it yet.

    4. Re:OS integrated DRM and Steath "hiding" technique by norkakn · · Score: 1

      Any clue how I can unDRM wmv files so that I can play them on a mac? (The ones that need WMP10, but that anyone should be able to view)

  34. Re:Who needs books!? by isometrick · · Score: 3, Interesting

    I think you may be right about the private sector, but I went to a presentation by someone in the Dallas FBI "cyber crime" unit, and I wouldn't exactly call him the cream of the crop. (Not that it means all of them sucks) The extent of his comments on analysis was the software they used. Encase was one he mentioned. The presentation included many deterrents to the technologically knowledgeable, with statements such as "Nimbda infects web pages." peppering the fairly contentless background. He seemed fairly uninterested in the deep technical aspects of his job ... he snuffed the few technical questions in the Q&A session and indicated that his division didn't have time to delve into deep technical issues.

  35. I have the book by jkitchel · · Score: 3, Informative


    ...and I'd have to say that the review was pretty thorough. I couldn't put the book down when I first got it (which would probably be true for any other self described nerd on here). Here's the link to the book's web site if you want to read anything about it. There is a sample chapter there as I'm sure there probably is on amazon or bn.com.

  36. Don't tease us by crisco · · Score: 1

    Is that postmortem available online?

    --

    Bleh!

    1. Re:Don't tease us by grub · · Score: 1


      I'm not sure. I have a spiral bound hard copy, I'll contact the author tommorrow and ask.

      --
      Trolling is a art,
    2. Re:Don't tease us by Johnny+Doughnuts · · Score: 1

      This is worth writing up a slashdot story for, but don't do http for the file, please make torrents instead, and host it on something like a suprnova torrent tracker. That should take the load.

  37. Re:Who needs books!? by iabervon · · Score: 1

    I've always wondered how people can claim they can 1:1 a drive that's been rewritten 70 times. I'd believe 1:71, but there's no way the tool could pick the only incriminating cycle out of 71 cycles without recovering all of them to examine. Alternatively, you could try overwriting your incriminating xfs disks with filesystems of non-incriminating images and text, and see if they quit when they find data.

  38. Re:Who needs books!? by stratjakt · · Score: 1

    you mean the FIF!

    --
    I don't need no instructions to know how to rock!!!!
  39. Re:FYI by the_mad_poster · · Score: 1

    That's because you're an idiot and you don't understand the concept behind referrer linking. Since that jackasses that post those links here are only looking to waste space so they can make money, it does not benefit anyone except them to encourage the behavior. If the link had been posted in the article where it was relevant, it would have been acceptable. However, it was posted in the body of messages only as board spam, which is not.

    --
    Alito: A vote for Alito is a punch in the eye to put that bitch back in her place!
  40. DMCA Vs legitimate security tools AND keys by NZheretic · · Score: 1
    1) The Digital Millennium Copyright Act of 1998 severely restricts the release of any tool which could be used to circumvent DRM technology.

    2) Cracking the DRM code is not the same as cracking the key used to encrypt each item of encrypted content. If the key is not accessable then the content cannot be decrypted without major difficulty . If the virus/malware retains the decrypt key only in DRM OS protected resident memory, then the key is not accessable to the user. Also it is possible to construct polymorphic virus code which encrypts the decode key in the virus startup code.

  41. Re:Who needs books!? by rcamans · · Score: 1

    you mean plead the filth!

    --
    wake up and hold your nose
  42. Re:Who needs books!? by winkydink · · Score: 1

    Serious analysis would take place in the lab in DC, not in the office of some schmuck in the field office cyber-crimes unit.

    --

    "I'd rather be a lightning rod than a seismometer." -Ken Kesey

  43. Google DVD-Audio crack by NZheretic · · Score: 1
    Your not looking hard enough.

    The point is that you have a lot of very clever people trying to reverse engineer the code, which exposes code which has often undergone very little peer review. Most of the times this also exposes vulnerabilities in the decoding software, some of which are remotely or locally exploitable.

  44. Fear stenography as data hiding method... by JoshMKiV · · Score: 1

    I know, I know, it was a typo... still funny.

  45. Re:Who needs books!? by dexterpexter · · Score: 1

    EnCase is not free to law enforcement, though, and can be quite expensive. As far as networked machines go, this requires the Enterprise edition, which has to be previously-installed to the machine.

    iLook, however, is free to law enforcement and government agencies and generates rather nice forensics reports. It doesn't have the same bells-and-whistles feel as EnCase does, but it is free and thus provides a nice tool to budget-strapped law enforcement agencies.

    However, the grandparent post's attitude is one which computer forensics can rely on. As long as people believe they are invincible, then it makes the job easier. They don't realize that, essentially using free tools, you can recover deleted files from their machine and find just about anything, including stuff hidden in slack space.

    Foremost is another free tool which works in file recovery. Very, very nice tool. I would say that last time we used it, we got more information out of it than EnCase, although I am not putting EnCase down by any means.

    --

    *-*-*-*-*-*-*-*
    "We are Linux. Resistance is measured in Ohms."
  46. Re:Who needs books!? by dexterpexter · · Score: 2, Interesting

    Computer forensic analysts are without a doubt some of the most talented people in IT period. Computer forensics is multi-discipline and analysts typically have backgrounds in engineering, programming, criminology, and languages. And why are you assuming that most computer forensics experts are in law enforcement? The best analysts are in the private sector, military, and government intelligence.

    Exactly. From my experience, the forensic analysts I have experience with came from Computer Science and Electrical Engineering backgrounds, and are highly trained. The "average nerds and hackers" fail to realize, sometimes, that the best among them sometimes cross the road to become these top-notch forensics analysts. It is not uncommon to find an ex-blackhat pop up in the private sector years later as a computer forensics analyst. In training, they bring in the guys who were on the "other side" and teach you to think like those guys, so that you can catch them.

    And the tools (iLook--which is free to law enforcement, EnCase, Foremost, etc., etc.) are fairly effective against your average case. Some people do not realize that even NASA has a computer forensics division.
    It is, however, the attitude of being invincible that makes most guys all the more catchable.

    As far as #1 goes, anything that doesn't fit under the Dauber rules of evidence (at least, if there is a good DA involved) will be quickly made null, but programs like EnCase certainly qualify.

    --

    *-*-*-*-*-*-*-*
    "We are Linux. Resistance is measured in Ohms."
  47. Re:Who needs books!? by kelnos · · Score: 1

    Hmm... From the feature list:

    * Mirror Copy -- Simple sector-by-sector copying for all proprietary partition types (e.g. MAC, Linux, SUN, OS6).

    I wasn't aware that Linux file systems were "proprietary"...

    --
    Xfce: Lighter than some, heavier than others. Just right.
  48. Re:Who needs books!? by dexterpexter · · Score: 1

    And if the case is too small they wont bother.

    This is partially true in that most crimes are taken on a "Big fish versus Small fish" basis. This is no different from traditional crime. In the case that a hacker hit a small business with very little effect, it is generally more practical for an incident response team to find out what happened, restore from a trusted backup, and then go about fixing the problem so it doesn't happen again.

    However, if you're trading kiddie porn or decide to peruse your local financial institution or any other institution regulated and required by law to report hacking incidents, I will guarantee that you become a "Big Fish" fairly quickly.

    And the range of forensic tools available to a good forensics analyst is likely to cover most anything you throw at it. You are correct in that local PD cyber crime units are often started by guys who have very little computer expertise and do not initially know how to get forensically-sound evidence. However, free software like iLook and expanded forensics education programs are changing that. And, if you do become a "Big Fish," you can almost bet that the guy assigned to your case knows what he is doing.

    --

    *-*-*-*-*-*-*-*
    "We are Linux. Resistance is measured in Ohms."
  49. Caches? by phorm · · Score: 1

    Well, if you're viewing kiddy porn then I'm probably not feeling sorry for you if you're nailed anyhow - however there are other factors. I think the easiest place to get nailed is cache. Either your browser cache or whatever. Unless you're pointing *that* to an encrypted FS (or the whole thing is encrypted, which is super-high overhead) you'll probably have something in there.

    The big problem I see is that you can have such things in your cache without being a pedo. How many pr0n sites advertise lolita pics, and there are fuzzy banners etc. I've had a few times where my normal pr0n-browsing misadventures have ended up with all sort of interesting popups (moz helps this, mind, but not always)... anything from animals to underage and other types of filth. Even if I haven't viewed it, the bazillion popups it spawns have probably nicely laced my browser caching will also sorts of incriminating crud.

    I've always wondered if those things would be used against you, but it probably depends on how bad they want to nail you or if they just don't like you. Hopefully I'll never have to find out, and lately moz has been doing a good job of blocking the popups.

  50. It's always the same by elh_inny · · Score: 1

    "[...]Sample topics include file attributes, alternate data streams, OLE and stenography.[...]"

    People always confuse these two words,
    stenography - typing fast on a weird machine,
    steganography - information hiding techniques.

  51. Dupe? by np_bernstein · · Score: 1

    Wasn't this posted on Tuesday?

    http://books.slashdot.org/article.pl?sid=04/11/0 9/ 202220&tid=192&tid=172&tid=6

    --
    RandomAndInteresting.comdefending the world from stupidity since 1979