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New Anti-Forensics Tools Thwart Police
rabblerouzer writes "Antiforensic tools have slid down the technical food chain, from Unix to Windows, from something only elite users could master to something nontechnical users can operate. 'Five years ago, you could count on one hand the number of people who could do a lot of these things,' says one investigator. 'Now it's hobby level.' Take, for example, TimeStomp. Forensic investigators poring over compromised systems where Timestomp was used often find files that were created 10 years from now, accessed two years ago and never modified."
Simple! Just cut the disk open and count the rings.
What?
This has got to be old news. Over 112% of Slashdotters have been using these programs for years, since at least 3 months from now!
- RG>
Hey pal, this isn't a pleasantforest, so don't waste my time with pleasantries!
I always just keep a few magnets handy... just in case....
I prefer hardware solutions, rather than software ones.
Timestomp? Now I've heard everything.
;)
Any hacker/script-kiddie with a working knowledge of touch and a 'find' command could wreak equal havoc. Combined with a quick filter and another perl script to generate random timestamps, all launched regularly from cron? Forget it. Forensics folks would be better off scouring logs for a non-tainted timestamp and counting directory inode entries for approximate age.
Of course, this says nothing of rootkits, which can be downright subversive, embedding themselves into kernel space where not even the OS knows they exist, where they can wreak untold havoc with historical system data or encryption. I bet there's even a script-kiddie version of anti-forensics tools out there, where it just cron-obfuscates anything trackable. Logs, timestamps, frequent automated sweeps of shred over unallocated disk blocks, inode reordering, and so on.
Now that I think about it, that might be a good idea. I got some work to do.
Read: Rabbit Rue - Free serial nove
The obvious message to law enforcement is that people don't like others going through their things.
Personally, I'm all for it! The timestomp tool they mentioned seemes more for oh-shit scramble-the-evidence rather than general usage... that kind of timestamp manipulation can really frig up a system.
Personally I'm a fan of disk encryption using algorythms and key-lengths that make it extremely impractical to get in once the system is powered down. If up however... you have three strikes at getting in and all future packets from your IP are silently dropped for several days. Local access isn't a problem either... open the case and power goes out... and after 10 minutes of idle-time the system locks (only way in is password or reboot... obviously reboot isn't helpful)
Call me paranoid. I am. I also like my privacy. Yes, I DO have something to hide: MY LIFE! I don't want you in my stuff at all!!! It doesn't matter that there is nothing illegitimate or illegal on the damn things, I still don't care.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
http://www.cio.com/article/print/114550 - Print version so you don't have to go through ten pages to read it all.
:)
Anonymous coward so no Karma whoring today.
Hate to sound like a apple fanboi, but even for those with something to hide that don't know much about computers at all, and therefore lack the know-how required to use these tools, simply using Mac OS X and turning on File-Vault, sad as it sounds, is enough to confound the majority of law enforcement. Most of the contractors that the police in the UK use are windows only. I know for fact that any linux or 'specialist' computers get passed to a specialist data firm in Germany for decoding...
Macs?
Only in the most serious of cases are macs in the UK sent for hacking if File-Vault's on. They go to Canada and take upwards of a year to crack. If ever.
Unless you've done something pretty fucking serious, and the police know the evidence is on the machine, just can't prove it, they usually won't go to the expense.
Of course, only the most stupid and inept of morons would be doing illegal shit and storing it on their computer without using the most powerful encryption possible, and only storing that which absolutely must be stored. Mind you, criminals are not usually noted for their cunning and intelligence....
It goes without saying that the above does not translate to across the pond, nor does it apply on Security operations with terrorists and the like. How MI5 & MI6 do things is completely different and tends to involve some 'specialist' people from the likes of the I-corps and in-house solutions....
I could elaborate, but I'm not THAT dumb.....
The truth shall always be free: Boris Floricic is Tron.
Let me let everyone in on a dirty little secret about 99% of police computer forensics experts... they are less skilled than most 9 year olds at recovering vital information. Many of them use bootable disks that just check the hard drive for IE's cached files and history, etc, etc. Simple stuff a child could do. These people aren't doing complex low level block analysis. They are doing the level of recovery parents do at the end of the night to see what websites their children went on. Does it surprise anyone then it's extremely easy to fool them? God forbid you use encryption, an OS they aren't familiar with, or hardware they've never seen. They'll never recover anything.
If an officer ever threatens to taze you, say you have a pacemaker.
By physically examining the disk you could better determine the age of the data -- but this is not how digital evidence is usually collected.
In fact, this just exposes how ludicrous courts' treatment of digital "evidence" is. The information they accept as evidence can be trivially faked. Think it sounds far-fetched to be framed for a crime? That's not so difficult when someone can just flip a few bits on your hard drive, maybe via a memory-resident-only exploit, then call in an anonymous tip to the police. There will be nothing on the drive to exonerate you. You could then easily spend years in prison for nothing.
It's like the situation we face now with electronic voting, but easier to defraud than even that. The people making these laws and procedures seem to have no idea how computers actually work.
My girlfriend told me that her nephew was going to college for "Computer Forensics" and my immediate response was, when he's done all he'll be able to do is catch cheating spouses. People who are engaging in real criminal activity are already using strong crypto and it's getting easier every day.
You just can't beat the numbers. If there is a 256 bit keyspace and a secure algorithm, you are not going to be able to crack the machine. I suppose that perhaps American and European law enforcement could take a page out of Israel's book and start using "strong persuasion" to get keys from suspects, but I don't imagine that happening any time soon.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
>>Five years ago, you could count on one hand the number of people who could do a lot of these things,' says one investigator.
Yes, yes.
Five years ago (2002) there were five people (or less) that knew touch.
Lol. The guy is a moron.
I remember walking through a parking lot in college in 1996 and listening to a couple guys talk about how they would touch their files to make late homeworks appear as if they were done on time.
About a year after that, UCSD switched to a turnin-based system. =)
The date a track was written could possibly be analyzed by looking at how it was written at the microscopic level, but this would probably destroy the disk itself. It would be very expensive. As far as I know, this is only theory and has not actually been done. If somebody has a technique, it would hope that it would require a lot of peer reviewed research to verify it's validity. Anyway, the date a track was written may have nothing to do with the age of the data (file), as the OS may move files around for efficiency. This will not effect the timestamps of a file. The fact is that these timestamps are simply data written on the disk and can easily be changed.
What would be interesting to me: a tool that deliberately modifies timestamps and/or creates ghost deleted files to tell a normal-looking story of computer use, when the actual history has been anything but.
In other words, forensics tools can assemble the history of file use on a disk. If it's known that the disk was in use before a certain date, but no timestamps can be found before that date (on current or deleted files), one may suspect the disk was wiped at that point. Likewise, physical disk usage for a given file system type has known and studied statistical characteristics over time. If the statistics are off, if you don't find deleted file images where you expect them, you may suspect that the freespace was wiped, or that certain unused disk space that would normally contain deleted file images contained files that are now wiped.
What happens when you have a tool that modifies timestamps on current and deleted files such that a normal distribution of them extend back before the date of disk wipe? Even worse, what happens if the tool can create "ghost" images of deleted files, in order to fool tools that look for normal statistical disk usage?
Once you have such a tool, wiping a disk and starting over can literally be done undetectably. So much for worry about having to maintain disk drive evidence after being hit with a subpoena.
Kythe
In 'Merica, we call it gitmo. Encrypshun don't fool us nohow, nosir.
'fter all, if yah ain't guilty, watcha hidin' stuff fer? Dontcha know there's a war goin' on?
The society for a thought-free internet welcomes you.
Got a little something to hide? The point wasn't to provide deniability for your kiddie porn. The idea is more like, you rooted my machine, stole my data or did something evil with it, and now you want to cover your tracks. So you toast the logs as well as you can, you jumble up mtimes and permissions on files so that someone going back and doing forensics has a harder time establishing a pattern. The first step towards finding out who did something is figuring out when it was done, to find out who had access at that time, where to look in (non-compromised) logs, etc. So if you obscure that information you make it a little harder to trace things back to you. It's about hiding an identity, not data.
If you think imaginary property and real property are the same, when does your house become public domain?
Imagine a filesystem that is encrypted 3 times, in "headerless" fashion. What I mean by headerless is, whereas a zip file leaves reliable signatures identifying it as a zip file, this scheme would be a naked 128 or 256 or 1024 bit encrypted file (bear with me here) with no signature. There would be no way to even identify this file unless you managed to decrypt it with the right password and the exact corresponding decryption scheme. (It could be a zip file or a rar file or an arj file but you'd have to guess.)
That's for the first layer. Then you use the same (or different) scheme to scramble that already encrypted file again. With the same or different password.
Then you do it a third time.
Granted this would take a hell of a lot of computing power and a single bit of data corruption would screw you royally (which calls for more advanced recovery techniques which leads to some weaknesses...), but the effect is this.
First, you get the hard drive and the whole filesystem is encrypted. It's utterly garbage to you. You don't know which scheme was used to encrypt it. You certainly don't know the password. But you may know it's triple layer encrypted. Or double, or quad.
What is certain is, if you get the correct encryption scheme AND the password for that first layer, the decrypted file is STILL GARBAGE. You don't really know if you got the correct information or not, because you're still looking at a "headerless" pile of garbage data. Good luck guessing that second layer because no matter what, you still get a pile of incoherent garbage.
If you've done this to all your files on your hard drives, DVDs and CDs, this is where you demand your Constitutional right (in the United States) to a SPEEDY trial and then plead the Fifth Amendment in court when asked for your password/encryption schemes. Why? Because if I'm right, the police and their descendants down to the 7th generation will have died of old age before they figure out the 2nd layer, much less the 3rd.
Mind you, the cops may have slapped a keylogger on your system ahead of time. If that's the case, you're screwed.
Lawyers and hackers, please rip my idea to pieces and tell me what you think...
--- Grow a pair, liberals... stop letting the Republicans bully you!
I read Ken Thompson's Reflections on Trusting Trust, it has always occurred to me that any computer crime is completely untraceable. It is only laziness on the part of the criminal which allows him to get caught. It is possible for someone to completely cover their tracks and leave no evidence of their actions.
But it is also possible to log every action a hacker does. Erasing the logs doesn't do much when the compromised system is virtually hosted and every action recorded for later playback - on a system which isn't even visible to the hacker. And consider the possibility of tracing at the network level. It is possible to physically connect an ethernet chip to a network and capture all traffic on the network without ever joining the network. That is, the card can sniff the wire in a read-only mode without ever publishing its MAC address or responding to ARP queries. Even if the hacker does use encryption, can he really be sure that his machine hasn't been rooted and keylogged? Can today's hackers verify even the microcode inside their processors and BIOS? If he can cover his tracks, so can the FBI.
How does a hacker know his rootkit isn't spying on him? Even if you have the source, a compromised compiler or assembler can still produce a compromised executable. Should you verify the executable by hand, you still have the possibility of a vulnerability in the processor's microcode. Something as simple as making any area of memory available to the NIC when a certain opcode sequence is executed could be hidden very well and provide a veritable back door to law enforcement.
Unless you are willing to build your own computer from scratch and never connect it to a public network, you can never prove that you aren't compromised. Sure, we can talk statistics and likelihood and incentives and human factors and whatnot, but it doesn't change two fundamental aspects of the computer:
Your averge user - heck, even most programmers and hackers - don't have the time to trace through every possible instruction path in the software they use. They aren't going to burn their own BIOS EEPROMs to be sure the BIOS isn't bugging them. They aren't going to surgically remove the processor's cover and verify the die pattern to be sure the microcode isn't compromised.
Instead, they're going to trust the responses their computer shows them. Just like the rest of us - it's a gamble. Maybe the hacker compromised a bank - or maybe, the bank is in cahoots with the FBI, and he's just knocked over the honeypot. He won't know until he goes to the bank - and withdraws his cash, or gets arrested.
Still a pretty big risk, imho.
The society for a thought-free internet welcomes you.
I don't mean to sound like a moron or naive but are Linux rootkits really that prevalent?
Considering that rootkits originated in Unix (hence "root"), I imagine that they are as prevalent in Linux as they are in any operating system (the argument of uptime notwithstanding).
Besides, a rootkit does not have to reside in kernel space to be very effective. Simply replacing many of the key binaries (init, bash, getty, ls, top, ps, etc depending on *nix flavor) will do wonders for probably 98% of systems out there. That said, I'm sure there are some which do reside in kernel space (a kernel module perhaps?) or maybe even some that are simply modified kernels (the source is available after all). How do you know that the kernel your system is running has not been compromised?
After doing a quick google search for "rootkits for linux", I found a few for the old 2.0 and 2.2 Linux kernels...
I tend to doubt you'll find the latest and greatest rootkit via Google. If you know the right people, I'm sure you can get whatever you need.
"What do you despise? By this are you truly known." --Princess Irulan, Manual of Muad'Dib
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I am an NSF–funded researcher in computer security, focusing on electronic voting. Data privacy and confidentiality is very important to us, as you can imagine.
Your idea is quite terrible.
First, what do you mean by a file "without signature"? Take a zip archive as an example--even if you strip off the zip header, any forensicist worth his or her salt can figure out it's a zip archive, just because of the way the data is structured. Encrypted filesystems have structure, too. A data forensicist can recognize an encrypted container on the basis of its structure. (Some people have recommended to you TrueCrypt in hidden volume mode. This is bogus. I'll explain that if you want.)
Second, you appear to not understand how crypto works. Two layers are better than one, right? So double ROT13 encryption is stronger than single ROT13, right? You're running smack into a major, well-known area of crypto. A lot of ciphers do not composite themselves well. You are almost always better off just picking one algorithm with a strong keysize than a composition of multiple algorithms.
Third, how do you plan on managing all of your keys? Key management is a thorny enough problem in the best of times. By relying on multiple keys you're multiplying the problem immensely.
You really need to do some basic research in crypto.
Disclaimer: I am a physicist.
As far as I know, there has not been one scrap of evidence showing that past disk writes can be examined through microscopy, or any other kind of direct physical examination.
The most powerful technique I know of would be Magnetic Force Microscopy (MFM), which is essentially a variant of AFM (Atomic Force Microscopy) that uses a magnetized tip. When I was an undergraduate, I used AFM to image surface features as small as 50 nm, which a quick calculation shows to be comparable to the square root of the physical area used to store a bit on a modern hard drive. Presumably, somebody with more experience or better equipment could do better; it's not a difficult technique if you just want to learn the basics. To actually scan a hard drive in a reasonable amount of time would require a very specialized MFM machine, but I see no reason why such things wouldn't be available to various three-letter agencies.
Now, I don't know whether there is any residual information to get from an overwritten bit, but it would surprise me if there wasn't, and if there is, it can probably be gotten with MFM, if not an easier technique.
withholding the password would be obstruction of justice
Couldn't you choose an incriminating password and plead the 5th?
This post written under Gentoo-linux with an SCO IP license.
The "flaw" pointed out by the GP is only a flaw if you're being tried in a kangaroo court. I don't think our court system has gotten that bad.
I mean, if you're dealing with a corrupt court where you're guilty until proven innocent, you don't even have to be using encryption to get screwed this way. The DA might just as well accuse you of using steganography to hide illegal photos in random files spread all across your hard drive, which is equally impossible to disprove.
I'm not sure what you mean by the "structured nature of the hidden volume", though. TrueCrypt hidden volumes have no plaintext header, just like main volumes, and as long as the crypto methods in use are good ones, the encrypted data will be indistinguishable from random bytes, no matter how well-structured the plaintext is.
There are attacks against hidden volumes, but they basically involve taking snapshots of the whole volume at separate points in time, then obtaining the main volume's key and checking whether any changes have been made to "unused" areas of the filesystem.
That is, I could sneak into your house and copy the disk today (version A), then come back next month, seize the disk (version B), and force you to give up the main volume key. I can then mount both versions of the partition and look for differences between them. If there are any areas that contained random data in version A, and different-but-still-random data in version B, I can be pretty sure it means you were writing to a hidden partition located there.
I think the best defense against that attack would be for TrueCrypt to randomly write chunks of new random data to the free space of mounted volumes, which would disguise the writes made to hidden volumes. (Of course you'd need to use both keys when mounting the main volume so it knew not to clobber your hidden data.)
Visual IRC: Fast. Powerful. Free.
In our court system, you are innocent until proven guilty, the burden of proof is on the state.
This is true for sufficiently high values of w, where w is your net worth. If you can't afford tens of thousands of dollars to fight a bogus charge, then you're effectively screwed, particularly if the charge is one of the very emotionally charged ones (child porn, rape, terrorism, etc.).
You'd quickly end up in a situation where you'd be facing a team of prosecutors, working with virtually unlimited taxpayer funds (gotta protect the children, right?), against your fresh-out-of-lawschool public defender, whom if you're unlucky, you might have to share with half a dozen other defendants. And chances are, they're going to believe you're guilty and (consciously or not) treat you like it.
There have been a lot of sociological studies and research done on the U.S. legal system. People who can't afford lawyers plead guilty at an astoundingly high rate, and the entire system is set up to "process" them as quickly as possible, from arrest through to prison.
The system works like you describe in the best case scenario, but even then, it'll probably leave you bankrupt.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
I believe the parent poster was speaking in terms of removing the platter from the drive and heating it in some sort of induction heater. This allows precise control of temperature and only directly heats conductive materials. Building one requires only some fairly simple electronics (scroll down for action shots).
You know they call 'em fingers but I've never seen 'em fing. Oh, there they go.
Encrypt once using a good algorithm. Multiple encryption is Hollywood-style security.
Xenu loves you!
Our justice system is run by elected officials (with media support). If you want fair treatment (justice) you had better hope that:
- it's not an election year
- the case has not generated a lot of media attention
- the case is not worthy of media attention when the DA holds a press conference
- the DA (and many others in the justice system) are not career building, and looking at your case as an opportunity to advance
The last one is the kicker. For every case there are dozens of people in the justice system that will get beneficial career advancement material from a successful conviction. That's my observation.