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Mystery Malware Affecting Linux/Apache Web Servers

lisah writes "Reports are beginning to surface that some Web servers running Linux and Apache are unwittingly infecting thousands of computers, exploiting vulnerabilities in QuickTime, Yahoo! Messenger, and Windows. One way to tell if your machine is infected is if you're unable to create a directory name beginning with a numeral. Since details are still sketchy, the best advice right now is to take proactive steps to secure your servers. 'We asked the Apache Software Foundation if it had any advice on how to detect the rootkit or cleanse a server when it's found. According to Mark Cox of the Apache security team, "Whilst details are thin as to how the attackers gained root access to the compromised servers, we currently have no evidence that this is due to an unfixed vulnerability in the Apache HTTP Server." We sent a similar query to Red Hat, the largest vendor of Linux, but all its security team could tell us was that "At this point in time we have not had access to any affected machines and therefore cannot give guidance on which tools would reliably detect the rootkit."'"

53 of 437 comments (clear)

  1. Should have used IIS by Anonymous Coward · · Score: 5, Funny

    This is why serious businesses choose a serious web server: Microsoft Internet Information Services running on Microsoft Windows Server.

    1. Re:Should have used IIS by Shaman · · Score: 3, Funny

      Hahahahahaha hah aha aha aha hahahahaaha bwahahahaha ...wait, you're joking, right?

      --
      ...Steve
    2. Re:Should have used IIS by uberushaximus · · Score: 4, Funny

      Of course not, this is internet, internet is serious business, we do not 'joke' here.

    3. Re:Should have used IIS by Niten · · Score: 4, Informative

      In all seriousness though, IIS 6 has a pretty darn good security track record; seemingly better than Apache 2's, even if it is blasphemy for me to say it. I've previously decried the use of raw vulnerability statistics to make comparative claims about different products' security, but I think the fact that such a widely-deployed product as IIS 6 has been found to have only a single remote access vulnerability in the last four years really speaks for itself.

      I mean, I'm just a Unix guy who's never had much use for a Windows web server, but that's my $0.02...

  2. Re:Ubuntu as well? by PrescriptionWarning · · Score: 4, Insightful

    "the current thinking is that the malware authors gained access to the servers using stolen root passwords"

    so basically its most likely they used the traditional means of gaining access (not through holes, but merely through bad personal security practices regarding passwords and password management). And it only affects windows clients. So how is this problem not your typical someone cracked your machine? Oh wait, I smell Microsoft FUD... ewwwwww

  3. Something's fishy! by linumax · · Score: 4, Funny

    Last night I discovered a directory named 53 4B 59 4E 45 54 in my home folder.

    1. Re:Something's fishy! by JeepFanatic · · Score: 5, Informative

      If you run those values through a hex to ascii converter you get SKYNET

    2. Re:Something's fishy! by Trigun · · Score: 5, Funny

      Are those Bra sizes? You're into some weird shit man.

    3. Re:Something's fishy! by sukotto · · Score: 5, Funny

      Yeah, mine had 4 8 15 16 23 42

      and all sorts of weird stuff's started happening in the server room

      --
      Come play free flash games on Kongregate!
    4. Re:Something's fishy! by geminidomino · · Score: 3, Funny

      I saw that on someone's shirt last week when I went to my spanish class at night school. I spent 25 minutes before class trying to figure out the pattern.

      Now I google it and I see it's from a dumbass TV show. I'm pissed off.

  4. Re:Funny by Undead+Ed · · Score: 5, Insightful

    According to the story (did you read it), it appears to be a situation where the root password has been compromised, not the applications or operating system.

    Problems with IIS were as a result of vulns in the application and/or Windows operating system - totally different problem.

    Would you blame a lock company if the user left his keys in the lock?

    Ed

  5. mkdir 1 by hey · · Score: 4, Insightful

    I can see thousand of people trying to make numeric directories :)
    Yes, also if you can run your tummy while patting your head you aren't infected also.
    I think.... this crazy idea is the virus!

    1. Re:mkdir 1 by padyer · · Score: 3, Informative
      That regex is b0rken. It matches any file of at LEAST 5 chars that ends in .js. The story at cPanel says that it is exactly 5 random chars and then the .js. Should be changed to

      tcpdump -nAs 2048 src port 80 | grep "/[a-zA-Z]\{5\}\.js'"

      Note the / at the beginning of the grep regex.

  6. LOLserver? by KublaiKhan · · Score: 5, Funny

    IIS are serious server. This are serious thread.

    --
    In Xanadu did Kubla Khan
    A stately pleasure dome decree
    1. Re:LOLserver? by Anonymous Coward · · Score: 5, Funny

      Is can be rootkit tiem now plz?

    2. Re:LOLserver? by davidsyes · · Score: 3, Funny

      That are be unpossible.

      --
      Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
  7. Re:Am I safe? by Anonymous Coward · · Score: 5, Funny

    Does this rootkit work on a hardened Gentoo install with no LKM support on SPARC64? :P

    Maybe; they're still compiling it.

  8. Read it careful people... by cbart387 · · Score: 3, Informative
    The servers are linux (because of an access issue. The computers being hurt by this are windows. At least that's how I read the article (see quote from article below).

    According to a press release issued earlier this month by Finjan, a security research firm, compromised Web servers are infecting thousands of visitors daily with malware that turns their Windows machines into unwitting bots to do the bidding of an as yet unidentified criminal organization. Security firms ScanSafe and SecureWorks have since added their own takes on the situation, though with varying estimates on the number of sites affected. All reports thus far say the compromised servers are running Linux and Apache.
    --
    Lack of planning on your part does not constitute an emergency on mine.
    1. Re:Read it careful people... by jawtheshark · · Score: 5, Insightful

      I do not know how you interpret this, but a rooted server, Linux, FreeBSD, OpenBSD or even Windows is also a "harmed" computer. Yes, clients will get infected, but the servers are in deep trouble too.

      --
      Ahhh...the great dumpster continuum. Many a free computer will be found there. -- sowth (748135)
  9. Re:Am I safe? by GreggBz · · Score: 4, Funny

    Yes, but you have to compile it.

  10. Re:Funny by plague3106 · · Score: 5, Insightful

    I read it, here's what it said: "One great unknown thus far is how the servers come to be infected. Absent any forensic evidence of break-ins, the current thinking is that the malware authors gained access to the servers using stolen root passwords."

    In other words, they have no idea how the servers were compromised. Because they can't find out how, they're guessing it was a root password that was stolen. In other words, its still just as likely a flaw in some software.

  11. Re:Software sucks. by Anonymous Coward · · Score: 3, Insightful

    How is that flamebait? I'm dead serious. If the quality of software doesn't improve dramatically, we're going to be in a world of hurt very soon. How do you suggest we achieve that improvement if not by making authors of faulty software liable for their negligence? We certainly can't keep upgrading software every time a bug is found, if bugs keep cropping up at the current rate.

  12. What are the common factors? by Arrogant-Bastard · · Score: 4, Insightful

    To figure out what the compromise vector is, it's probably going to be necessary to figure out what the compromised servers have in common -- and how that differs from uncompromised servers. (Keeping in mind that currently-uncompromised servers may have the same vulnerability, and that attackers or their software just may not have gotten to them yet.)

    I'd suggest enumerating factors such as OS, OS version, remote access methods (ssh, ftp, etc.), Apache versions, Apache modules, add-ons like CPanel, network/ASN, and so on -- anything could be a culprit at this point.

    And that includes things that have nothing to do with Linux or Apache: for example, it's possible that the attackers acquired root passwords by infecting Windows systems used by administrators -- then just waited for them to initiate ssh sessions to their servers. It'd probably be best to leave all possibilities open and consider them equally likely until evidence starts accumulating in favor of/against them. (In re-reading that last statement, I suppose it sounds a bit trite. I'm just trying to discourage premature conclusions that anything is at fault until somebody can produce evidence to support saying so.)

    1. Re:What are the common factors? by whoever57 · · Score: 4, Insightful

      To figure out what the compromise vector is, it's probably going to be necessary to figure out what the compromised servers have in common -- and how that differs from uncompromised servers. (Keeping in mind that currently-uncompromised servers may have the same vulnerability, and that attackers or their software just may not have gotten to them yet.)
      Perhaps this is the end result of all those dictionary attacks against SSH servers that we have seen for the past 2-3 years. Inevitably, some of those attacks will have been successful. Perhaps the successful logins have not ben exploited until now.
      --
      The real "Libtards" are the Libertarians!
    2. Re:What are the common factors? by imipak · · Score: 3, Informative
      Apparently it's not Cpanel.

      Other info as of last week:

      Various discussions:
      http://www.webhostingtalk.com/showthread.php?t=651748
      (useful discussion starts on page 3 or so)
      http://www.theregister.co.uk/2008/01/11/mysterious_web_infection/
      (describes the inability of ScanSafe to work out what's happening)
      Trend have a piece on their blog:
      http://blog.trendmicro.com/e-commerce-sites-invaded/
      SANS/ISC
      http://isc.sans.org/diary.php?storyid=3834&rss

  13. The register's older writeup on this ... by chris.dag · · Score: 5, Informative

    The Register has been on this for a while and although the story is older it is better written and has more interesting details: http://www.channelregister.co.uk/2008/01/16/mysterious_web_infection_continues/

    my $.02 of course

  14. ssh + bad password by Panaflex · · Score: 5, Informative

    I see this type of attack all the time, the fact that someone automated it and gave it a zombie machine is not surprising.

    * Don't allow root to ssh into your machine.
    * Disable ssh1.
    * Limit sudoers.
    * Have good passwords.
    * ???
    * PROFIT!!

    Seems like a formula everyone should know.

    --
    I said no... but I missed and it came out yes.
    1. Re:ssh + bad password by ls671 · · Score: 4, Interesting

      You should also have some process that completely blocks ssh login attempts from a given IP after so many failed login attempts instead of letting the hi-jacker poll your machine for as long as he wishes.

      --
      Everything I write is lies, read between the lines.
    2. Re:ssh + bad password by Crimsonjade · · Score: 3, Informative
    3. Re:ssh + bad password by Niten · · Score: 4, Informative

      I'll see your good point, and raise you a pf.conf snippet:

      ### MACROS AND TABLES SECTION
      table <wan_bruteforce> persist

      ### PACKET FILTERING SECTION
      block in quick on $if_wan inet from <wan_bruteforce>
      # ...
      pass in on $if_wan inet proto tcp from any to ($if_wan) \
      port ssh flags S/SFRA synproxy state \
      (max-src-conn-rate 3/30, overload <wan_bruteforce> flush global)

      That's how you can block non-massively-distributed password dictionary attacks on the BSDs, anyway. Sadly, the fact that OpenBSD's firewall can perform this task on its own means that we probably won't see this feature worked into OpenSSH itself any time soon -- so on Linux you'll need a third-party script such as DenyHosts, as others have already pointed out.

      (And yeah, unlike this PF configuration, DenyHosts lets you synchronize your table with a sort of universal blacklist of blocked hosts, so some might choose to run it on BSD anyway. It sounds like a good idea on paper, but boy does it suck when your home IP address keeps inexplicably winding up on the blacklist due to what turns out to be a single site's massively misconfigured server.)

      But I think the most important lesson to be learned here, assuming that this thing does turn out to be an ssh attack, is that allowing single-factor, password-based administrative logins to a highly connected host is never a good idea. If you have the luxury of complete control over the site and its users (or are simply a highly empowered BOFH), disable password-based logins entirely and force the use of ssh public keys:

      # /etc/ssh/sshd_config
      PubkeyAuthentication yes
      ChallengeResponseAuthentication no
      PasswordAuthentication no
      KerberosAuthentication no
      GSSApiAuthentication no
      UsePAM no

      As a concession, if you want to ensure access without having to carry around an encryption key on a USB dongle, on Linux you can use PAM and libpam-opie to set up secondary access using a dual-factor combination of an S/Key one-time password and your regular login password (S/Key is like Steve Gibson's much-trumpeted "Perfect Paper Passwords" system, which is ingenious in its own right, except that S/Key is designed so that you don't need to keep your secret key stored unencrypted on the very server you're worried about protecting):

      # /etc/ssh/sshd_config
      PubkeyAuthentication yes
      ChallengeResponseAuthentication yes
      PasswordAuthentication no
      KerberosAuthentication no
      GSSApiAuthentication no
      UsePAM yes

      # /etc/pam.d/ssh
      auth requisite pam_opie.so
      auth required pam_unix.so nullok_secure

      With the above configuration you can still log in seamlessly using your ssh private key. But if you get stuck somewhere without access to your private key, you just pull your S/Key passwords list out of your pocket and enter the next password in the sequence, as prompted, followed by your login password. This PAM configuration has the nice property that if you enter the correct S/Key password but then an incorrect Unix password, you will be asked for the next one-time password in the sequence before you can continue: so unless your attacker is exceptionally good at plaintext attacks on large cryptographic hashes, a successful brute-force attack becomes impossible.

      Wow, this post got a lot longer than I wanted it to... I'm, um, going out to get some fresh air or something.

    4. Re:ssh + bad password by Panaflex · · Score: 3, Informative

      Sorry, I wasn't clear:

      I've had admins on my network simply copy both pub & private ssh keys from server to server (they're in the same directory). They leave the private keys on the machine and forget or don't know what they've done. An attacker with root on that machine can then su into the account and access other machines.

      --
      I said no... but I missed and it came out yes.
  15. Re:Funny by Undead+Ed · · Score: 5, Insightful

    "they're guessing it was a root password that was stolen"

    A pretty good guess, otherwise we could expect to see millions of Apache web servers compromised (there are over 75 million Apache web servers in active service) and anticipate a much greater number of Windows clients infected.

    The significance of this story is not that Windows clients are the target, the significance is that the infecting agent is originating from Apache/Linux servers.

    Ed

  16. Re:Funny by studpuppy · · Score: 5, Funny
    Would you blame a lock company if the user left his keys in the lock?"

    Depends. How good is my lawyer?

    --
    The last time I wrote code, it was Morse
  17. Re:Am I safe? by bigredradio · · Score: 5, Funny

    Your safe. NOTHING will run on that system. ;-)

  18. Re:Software sucks. by vux984 · · Score: 4, Insightful

    It's high time for better software, and the only way to get that is to apply market pressure. Software liability is the answer.

    1) If the market really wanted extensive 'software liability' then we'd already have it. Customers would demand it, suppliers would figure out how much it would cost to provide it, and prices would sort themselves out. Turns out the prices go WAY up, and customers (most of them) don't want to pay them.

    2) What happens to Linux in a world with mandatory software liability? Who is liable? The company providing install and support? The volunteer contributor who wrote that line of code? The project maintainer who accepted the patch? ... And you wonder why your post was modded flaimbait?

  19. Re:Ubuntu as well? by symbolset · · Score: 3, Insightful

    It's possible to install software on a Linux webserver that exploits vulnerabilities in Windows clients. This is news?

    Here's a shocker: it's possible to exploit Windows boxes with services hosted on a Commodore64.

    Windows has more malware packages than legitimate software packages. They've really solved that ease of installation problem.

    --
    Help stamp out iliturcy.
  20. Re:Software sucks. by Schraegstrichpunkt · · Score: 4, Funny

    Yeah. People should be held liable when they know full well that Microsoft has a track record for bad security, but choose Microsoft products anyway.

  21. Re:Ubuntu as well? by nicklott · · Score: 4, Insightful

    Microsoft? This story is on posted on linux.com and being hyped on a OSDN site, where do microsoft come in? They must have a pretty deep mole to get this one planted...

  22. More details are available... by Anonymous Coward · · Score: 4, Informative

    ... though a solution has not been yet:

    http://blog.trendmicro.com/e-commerce-sites-invaded/

    If you happen to have one of these compromised systems, I am sure that Trend would like to talk to you about it...

  23. Re:Ubuntu as well? by Anonymous Coward · · Score: 3, Funny

    "but his point is that unless you are running Windows OR have an Apache webserver this doesn't effect you."

    Well I am sure the 3% of the population that don't fit into either category are relieved as hell.

  24. I'm not sure I buy it by mlwmohawk · · Score: 4, Insightful

    There is something suspicious about this report. Some things can't happen the way people say they happen, and when that is the case we have to look at more likely scenarios.

    I would bet the path of the TCP/IP packets route through compromised providers who have an injection strategy. Remember a few months ago how IPSs were injecting their own java script and ads into the pages of other sites?

    http://ars.userfriendly.org/cartoons/?id=20070703

    This is the most likely scenario I can think of.

  25. Re:Ubuntu as well? by BorgCopyeditor · · Score: 3, Funny

    But why male models?

    --
    Shop as usual. And avoid panic buying.
  26. Re:Software sucks. by mlwmohawk · · Score: 4, Insightful

    Software has to suck because the market can't afford software that doesn't suck. Kids out of high school and collage or fresh out of joe's web school. aren't qualified to write good software, yet this is what companies hire over more experienced people.

    Even then, there is no ability to develop your skills because you spend 99% of your time learning new environments.

    Software is HUGELY complex these days and it takes a log of study, knowledge, and skill to be any good at it. Companies don't want to hear that. They want to increase productivity by "KLOC." (Un)fortunately, there is a lot of "art" and "creativity" in software development and without well defined product specs, rigid test plans, and quality assurance which adds delays and cost to a project you won't get better code.

    Standard business upside potential vs downside risk. Upside potential: first to market, profit!!! Downside risk: blame some hacker.

  27. Re:Ubuntu as well? by wall0159 · · Score: 4, Funny

    What's this nonsense? Ubuntu is Ubuntu. ...and that's kinda related to Mac, right? Just... more browner.

  28. Re:Is Idiocracy coming true? by zcat_NZ · · Score: 5, Funny

    happy geek has run out of happy :-(

    --
    455fe10422ca29c4933f95052b792ab2
  29. Re:Ubuntu as well? by Christianfreak · · Score: 3, Insightful

    Exactly. Also this gem from the article:

    Other than using and safeguarding secure root passwords, not much can be done at this time to be proactive in preventing servers from being compromised,

    Turn off root's log in and get rid of cPanel and similar programs as well. I understand the need for an easy to use remote admin tool (as much as I'd love people to actually learn the shell), but can't we do better than a web-based program for this stuff?

  30. Re:Can't be malware by geminidomino · · Score: 3, Insightful

    It's for Apache/Linux so it must be well crafted code written with the best intention.... Then how do you explain PHP?

    *sniff sniff* Is something burning?
  31. Re:Ubuntu as well? by stuntpope · · Score: 4, Insightful

    His main point was insightful. There are two parts to the story - one, Linux servers running Apache have been compromised. Two, these servers are infecting Windows clients through vulnerabilities in those clients. This exploit does not affect non-Windows computers.

    If the current thinking is indeed that the Linux servers were inappropriately accessed through stolen passwords, how is that a security flaw of Linux or Apache? Like he asked, how is using a legitimate password equal to cracking the server?

    On the other hand, turning Windows clients into bots *IS* an example of that software's (and QuickTime's and Yahoo! Messenger's) insecurity and vulnerability!

  32. Re:Fail2ban by whoever57 · · Score: 4, Informative

    Fail2ban is another nice way to deal with these brute force attacks.
    You can use fail2ban, but SSH can be protected very nicely with Netfilter/IPTABLES -- just limit the rate of new connections to something like 3 per 3 minutes for each host and this will slow down any dictionary attack to the point that it is very unlikely to be successful.
    --
    The real "Libtards" are the Libertarians!
  33. Re:Funny by cp.tar · · Score: 3, Funny

    How many lawyers are good?

    I think their class restricts them to Lawful Evil; should they change alignment, they et disbarred. So, none, at a guess.

    --
    Ignore this signature. By order.
  34. Re:Ubuntu as well? by Skrynesaver · · Score: 3, Interesting
    There is no more powerful, nor easy to use, (with training), remote control tool for servers than ssh.

    GUIs provide metaphors for users, they have no place in administration.

    </grumpyOldFart>

    --
    "Linux is for noobs"-The new MS fud strategy
  35. Re:Hummm, no ahah ?! by Detritus · · Score: 3, Funny

    He's on a little-endian system.

    --
    Mea navis aericumbens anguillis abundat
  36. Comment removed by account_deleted · · Score: 4, Informative

    Comment removed based on user account deletion