Microsoft Warns of Impossible to Clean Spyware

darkjedi521 writes "The Inquirer has a story that the next generation of Windows spyware and exploits are starting to make use of "kernel rootkits". A paper at Microsoft Research has details on a prototype detection tool. Computerworld has more details, as well." From the article: "Newer rootkits can intercept system calls that are passed to the kernel and filter out queries generated by the software. This makes them invisible to administrators and to detection tools..."

Unpossible to Clean SpyWare?

Microsoft researchers have developed a tool, named "Strider Ghostbuster" that can detect rootkits by comparing clean and suspect versions of Windows and looking for differences.

Sounds almost malaprop. "It works, I threatened to rip a copy of Ghostbusters II onto my HD and I heard a tiny scream! My spyware aragorn!"

However the paper admits that the only way to be sure that you have killed a kernel rootkit is to completely erase an infected hard drive and reinstall the operating system from scratch.

That sounds rather drastic. How about drilling a hole through it, smashing it with a sledgehammer and throwing it into the Tiber while you're at it? Microsoft seems to be making a stronger case all the time for not exposing a Windows PC to the internet. Maybe it is time to look at a Mac.

Microsoft's XBox Firewire [technewsworld.com]

Re:Unpossible to Clean SpyWare?

I agree it's extreme. They should offer a downloadable bootable CD that verifies the checksums of all system files.

Re:Unpossible to Clean SpyWare?

I agree it's extreme. They should offer a downloadable bootable CD that verifies the checksums of all system files.

Not likely, as you and I may have XP Developer Edition, but where are you in your patches? Hmm?

Seems the best way to handle this is to run all browser processes at a very low security level.

Re:Unpossible to Clean SpyWare?

Not likely, as you and I may have XP Developer Edition, but where are you in your patches? Hmm?

And what's hard about that? It's exceedingly unlikely that any particular version of any Windows system file will have the same MD5 checksum as a trojaned version. Plus, if you know that patch X contains this list of files with this list of checksums, you can determine what patchlevel it has. It's not easy to do as it takes some intelligent coding, but it's far from impossible. Or just go the lazy way -- based on the different versions of each file Microsoft has released, you will know that the file is either good (because of all the patched versions Microsoft has released, its MD5 checksum matches one) or the file is bad (because its checksum doesn't match one released by Microsoft).

Re:Unpossible to Clean SpyWare?

And when that day comes, I will be amazed at the greatness of the hackers. Given the complexity required just to find a trivial collision [wikipedia.org] in MD5, the Earth will likely be destroyed in WWIII long before someone managed to get a complex trojan to generate the same hash value. But even still, it's easy to work around that -- just calculate hash values using several different hash algorithms. Given the odds of successfully finding a collision which matches, say, both MD5 and SHA-1, the universe will have long imploded by then.

Re:Unpossible to Clean SpyWare?

One of my job functions at the university where I'm employed is to fix student computers. 95% of the calls we receive are spyware/virus related. We have stopped trying to disinfect Windows from inside the operating system because it is pointless - there is no way to clean everything off from within the operating system. What we do is boot off of BartPE [nu2.nu] bootable CD, connect to the network, update the virus scanner & adaware, and clean off the hard drive. Then we proceed to boot the computer into windows to finish the final clean-up.

So, it surprises me that a report about this kind of ad-ware/viruses is just now coming out because we have been dealing with impossible-to-remove software for at least a year now. Fortunately the only way to defeat a BartPE scan is to install a BIOS virus - and almost nobody does that any more. :-)

Re:Unpossible to Clean SpyWare?

I've been using BartPE for a year now. The inital basic setup is very easy. It's also easy to customize it to add in your applications. Well, it's easy to add it into BartPE (loadable .inf files) , but sometimes you have to do a LOT of digging into Windows and the specific application to determine WHAT you need to add to said .inf.

My BartPE disk has Ad-Aware SE, and I use SFX to make self-extracting executable of Spybot. For AV stuff, I use Mcafee GUI plugin for their command line scanner, and Sysclean (by the same folks that make pc-cillin). Also Mcafee's Stinger is loaded, too.

I put it on a CD-RW, and once a week d/l the updates, then use the Bart PEBuilder program to rebuild an ISO, and burn that to a CD-RW.

Virus scans, spyware files... all are gone without having to boot into the compromised OS. Registry cleaning requires you to boot into the OS, but once the files are gone, that makes it a lot easier to clean.

It's not 100%, but it vastly improves the chances of fixing the system, with minimal time (30 mins a week to get the updates, 20 mins of actual work running the Bart disk to clean a system)

Re:Unpossible to Clean SpyWare?

Check the 911 forums (Bart links them from the Nu2 site) for modified Ad-Aware plugin that uses RunScanner. It'll let you scan the host system's registry from within Bart. I've added it to my latest builds this week, and it's been a great time saver and seems to work well.

I'd link you myself, but I'm stuck on dial up at the moment. :)

Re:Unpossible to Clean SpyWare?

If you want to build a BartPE disk, check out The Ultimate Boot CD for Windows [ubcd4win.com]. It's a massive collection of plugins and drivers for BartPE. Adaware, Hijack this, McAffee, defraggers, etc. Here's a list of apps it comes with [ubcd4win.com].

Hands down, bar none, the best place to start your BartPE plugin collection.

Re:Unpossible to Clean SpyWare?

The only problem being that Joe User won't think of downloading until the first sign of trouble. Which could mean that he's running \/\/1nd0z3 already, which means any downloaded CD image from that point in time forward can be made to appear bona fide.

A bootable CD with a checksum or digital signature checker ought to come with the system.

Re:Unpossible to Clean SpyWare?

They should offer a downloadable bootable CD that verifies the checksums of all system files.

At first glance, it even seems like it would be fairly trivial to build one yourself assuming that you can maintain a clean set of files to generate checksums from. Once you have the files you can use the live distro and checksumming tool of your choice to do the comparisons and replace suspect files accordingly. However...

The obviously problem is going to be dealing with DLL hell, especially if you want to include third party DLLs in your scanning tool. There are dozens of legitimate versions of some DLLs out there, especially for widely deployed things like the expoitable GDI DLLs that were at the centre of a "critical" patch a few months ago. Best of all, some apps are coded to require specific versions of those files and refuse to work with other versions. Yes, that's appallingly broken and terrible design, but it does happen, and checking the embedded DLL version number is no help - what's to stop a rootkit replacing a DLL's with a version with an unused version number? How would you deal with an unknown version of a critical DLL in a known shared file directory for a third party vendor that wouldn't confuse a typical user? Ignore it, and risk missing a rootkit? Delete it, and risk breaking an application (providing an option to restore it being an obvious safety net)? Or give the user a choice they probably won't understand between the two previous options?

Re:Unpossible to Clean SpyWare?

Except that's the recommended course of action for a rooted UNIX/Linux/BSD machine too (along with figuring out how it was rooted, plugging the hole, and preserving any evidence).

It's recommended, but not 100% necessary.

With Linux, you can boot from a live CD and validate every file and package on your system.

You can even chroot the system, wipe the boot sector and re-install the kernel.

This might be "impossible" to clean on Windows, but on Linux, it's just really annoying.

Re:It's recommended, but not 100% necessary.

That's why patching local privilege escalstion bugs is important.

Re:It's recommended, but not 100% necessary.

You keep a LiveCD with MD5 hashes for the current versions of all of your binaries?

Step 1: Take you Fedora or whatever installation cd's with all the original RPM files.

Step 2: Issue the command: rpm -Vp *.rpm

Step 3: All files that have a "5" in front of them have a wrong MD5 checksum.

Re:Unpossible to Clean SpyWare?

I prefer to have read-only filesystems. That way, every reboot guarantees a clean system.

You think it's a joke, but actually I do almost exactly that: for the few times I actually do need to use Windows, chiefly to use AutoCAD, I boot Win98 in VMWare and set it to always return to the hard-disk snapshot it booted with. That way, I can get as many xyz-wares on the Windows box, it'll always come back pristine the next time I restart it. And whenever I need to install something new, or change something in the Windows install, I do it carefully and take a new snapshot when I'm happy with it.

Honestly, VMWare is the best way to use Windows :-)

Re:Unpossible to Clean SpyWare?

"Honestly, VMWare is the best way to use Windows :-)" You could not be more right. I have been advocating VMware before, but for a reason.

I have set up 98SE, 2000Pro, XP environments (clean) under VMware and can easily create a 'clean' environment to test stuff. The snapshot feature is excellent, just snapshot the VM in question and if/when the software fucks up, restore.

The virtual hardware is the same every time. No driver issues. In fact, the current desktop PC's are so fast that it would make sense to run Winblows in them exclusively under VMware.. just store the user dirs on server. Get a new PC? Just copy the virtual disks and configuration.

I've been using VMware since its introduction and am currently using the 4 (and 5beta) versions for desktop use. I've had no use for the expensive server version yet since most of the servers are already running Linux.. but for those legacy Win32 apps VMware is really a blessing. Even been testing BSD's and SuSE distros with it.

Re:Unpossible to Clean SpyWare?

Maybe it is time to look at a Mac.

Kernel-level rootkits have plagued Unixes (including Linux) for a long time. Fortunately on Linux most suck, and can be detected with chkrootkit (yet how many out there that aren't detectable...), and (this is true for windows as well) any of them can be found simply by inspecting the drive from a known clean boot media.

Removing rootkits (kernel level or not) from any OS requires either guruhood, an exact knowledge of which rootkit(s) was used and what files they trojan (as well as a clean source to restore those files from), or a reformat-reinstall-restore(dataonly)frombackups.

Re:Unpossible to Clean SpyWare?

Of course, there are standardized tools to generate md5 sums of files. A good rootkit, before replacing a file, determines the md5 checksum of the file. Then, when then easily-detectable standardized tools ask for the checksum, the rootkit intercepts the request and feeds the tool garbage. Of course, there are countermeasures you can take, but they will tend become standardized, leading to counter-counter-measures.

What it boils down to is GIGO. If you don't trust to code running on your system, you can't trust ANY result reported by the system. The only solution is to force the system to run code you trust - ie boot to a floppy or CD.

Re:Unpossible to Clean SpyWare?

It would be fine if the ADMINISTRATOR had the ability to sign code for Palladium.

Yes, it is the same problem

R00tkits will get installed on Macs the same way they get installed on Linux: through a combination of two exploits. First, the hacker uses an exploit to obtain shell access with an unprivileged account Typical exploits include holes in Samba or CUPS (which OSX also uses), browser bugs (e.g. libpng overflows), holes in various daemons (if you use your OSX as a server), or even simply using a keylogger on a public machine to catch a user's password.

Then, the hacker uses a second exploit to elevate his local shell access to local root. Typical exploits of this nature include thread race conditions in the kernel, the kernel failing to properly sanitize input, or problems when a process is shifted from one kernel security infrastructure to another. The Linux kernel had a number of local root exploits in the past few months. IIRC Apple usually doesn't publish its list of security vulnerabilities (it just puts the fixes on Sofware Update, without fully explaining what they fix), so I can't comment on the security of the darwin xnu kernel.

Thus, I would say it's about as easy to install a rootkit on a Linux workstation as on an OSX desktop (and similarly, it's as easy to install a rootkit on a Linux server as on an OSX server). In other words, you need an unpatched system vulnerable to a specific pair of exploits, a clueless admin, and a skilled hacker -- which is not an impossible combination.

Re:Unpossible to Clean SpyWare?

Argh! This is one of the most blatantly obvious mistakes that always get modded up on Slashdot.

Yes, absolutely every general purpose OS can be rooted, spywared, hacked, or otherwise compromised.

By analogy, anything can kill you, poison can kill you, water can kill you, a bullet can kill you and a butterfly can kill you. Being possible is not the same as being probable.

In the binary, off/on, sense, security can theoretically be compromised. But we don't live in theory, we live in practice. There are no known kernel exploits for Mac OS X, there is no known spyware, there are no known viruses, there have been a handful of OS X specific exploits that require the user to run a program (and generally ask you to supply an admin password), and have all been "proof of concepts". The bulk of OS X security updates have been for Open Source/Unix apps, which are all turned off by default, and have never been reported as actually exploited.

It's virtually impossible to just randomly get rooted, trojaned, hit by a virus, or otherwise find your Mac is pwn3d. On Windows, you need to be fairly diligent, and even then you can't be sure.

You gotta ask yourself why this is. The answer isn't just "Windows is more common" (although that is a part of it. Windows is inherently flawed from a security standpoint. Mac OS X is inherently secure (relatively speaking). That doesn't mean it's impossible to hack a Mac, but it does mean that the risks are fewer, and are far more easily mitigated.

When someone says, "Windows is malware-ridden, I'm switching to a Mac" (sometimes a toothless threat, sometimes not), the response, "but it's possible to write a rootkit for Mac OS X too," is not a counter-argument. It's, at best, a warning that someday that Mac might possibly, but not very likely, get a virus or something... maybe, probably not though.

Re:Unpossible to Clean SpyWare?

There are no known kernel exploits for Mac OS X, there is no known spyware, there are no known viruses, there have been a handful of OS X specific exploits that require the user to run a program (and generally ask you to supply an admin password), and have all been "proof of concepts". The bulk of OS X security updates have been for Open Source/Unix apps, which are all turned off by default, and have never been reported as actually exploited.

That's because the open source apps have all their exploits reported as separate incidents, with incident IDs and so on. Apple (and Microsoft) slipstream security fixes into other patches all the time and just don't report them.

For Microsoft this technique is no longer useful because hackers reverse engineer the patches to determine the security flaws.

Rootkit cleaning

As far as I know, rootkits like that have been the norm rather than the exception on Linux and, I think, the BSDs for some time. I don't know about the other UNIXes and UNIX-like OSes (like MacOS/X), but I'd be surprised if it wasn't the case to some extent there too.

It's been widely recognised for a while that if your system is cracked, the only way to be fairly sure you've cleaned it is to reformat it and start again then *carefully* restore data from backups. I don't see how this is news.

Re:Unpossible to Clean SpyWare?

That sounds rather drastic.

Um, dude, a rootkit for *any* OS that hides itself by intercepting kernel calls is effectively uneradicable except by total reinstall. How the hell would a Mac save you from that?

Re:Unpossible to Clean SpyWare?

Macs are magic! Don't you read Slashdot?

OSX definitely has some positives.

OSX is more secure in many ways. For those that know what they are doing... (they usually don't get infected but that's beside the point) you can use the "chflags schg " command as root to lock a file so that it cannot be modified. The flag can only be cleared in single-user mode. Standard linux distros with ext2/ext3/reiserfs don't have that. I'm not real up to speed on WinXP or 2003, so I don't know if they have a single user mode (or a real multi-user mode ). But OSX can be hardened to where you can be sure the kernel or critical libs cannot be updated.

Impossible commands...

Wow, Microsoft must think this command is impossible:

A:\> format C: /AUTOTEST

Re:Nothing is impossible to clean

Reinstall windows.

Funny how many people seem to take this lightly. The way I see it:

Reinstall Windows

Reinstall all Software, include some pesky registrations

Update all drivers to where you were before hand

Put back all your customizations, default settings, etc.

Yeah, not impossible, but makes a boot to the head sound appealing.

Re:Nothing is impossible to clean

> Yeah, not impossible, but makes a boot to the head sound appealing.

Well, you can make a custom XP CD slipstreamed with SP2 including all of your drivers and programs that get installed automatically.

It's not quick, and it's not for Mom and Pop, but once it's done, reinstalling is a breeze and the time spent pays off the first time you use it.

Re:Nothing is impossible to clean

The installation for Windows XP is so damn tricky that the common Windows user wouldn't have a hope in hell of completing it.

Is this a joke? You boot off the CD and then the most complicated thing you have to do from there is choose your timezone. You don't have to know anything to install Windows XP...

Re:Nothing is impossible to clean

OH BS... unless XP has the drivers you need bundled with it, you aren't connecting to a network, and you're only planning on using solitaire and not gaming, there's a lot of work to do to get a system installed right. Oh, hope the user doesn't start with a pre SP1 install.. connecting to the network will be really fun then.

Re:You're infected! Not me.

In the old pre OS X days, most Mac viruses were INITs (AKA Extensions) which are rewritten system calls. I remember a virus from the olden days which was an INIT that spread through a DiskInsertionEvent.

Re:You're infected! Not me.

You're telling me that when joe user installs his linux version of kazaa and it pops up the message, you must install with root... enter password... linux solaris, mac, anything will be immune to the malware? I think not. Users dont read popups. If they are prompted for root... they will type it in.
Ive even seen macromedia flash boxes pop up to alert you that IE has blocked their activeX script, and the user should do the following steps to install the plugin. And people do.

This isn't really a problem

There's a very simple SOP for Windows users that will completely eliminate the need for a fix:

1. Buy new PC
2. DO NOT PLUG IN NETWORK CABLE
3. Image drive to external storage wth Ghost or the like
4. Unplug external storage
5. Plug in network cable
6. Connect to Internet. Save any info needed for storage.
7. Unplug network cable
8. Print all info obtained in step 6
9. Plug external storage back in
10. Restore image made in step 3
11. File hardcopies in cabinet
12. Knock back 3 or more shots of your favorite liquor
13. Unplug network cable
14. Return to step 3 for new Internet sessions

What could be simpler?

Re:This isn't really a problem

Yeah. You got me. I typoed "unplug" when I meant "plug in." You win. I'm deeply ashamed. I wish you a wonderful weekend celebrating your decicive victory here today. Kudos.

Re:This isn't really a problem

Deep Freeze [faronics.com] is much simpler.

Re:This isn't really a problem

What could be simpler?


Either install a non-Windows OS on your existing hardware or buy a Mac. Linux, any BSD, or Macos X are simpler choices. BSD or Linux are harder in the short run but require less on-going maintenance once the user is settled in. Macos X requires changing both hardware and software, but is likely to be an easier transition for most users.

Whether you like it or not, the Wintel platform is no longer a very good choice for the average computer user, and has become a quite unpleasant environment for most people.

Re:This isn't really a problem

1. Knock back 3 or more shots of your favorite liquor
2. Buy new PC
3. DO NOT PLUG IN NETWORK CABLE
4. Image drive to external storage wth Ghost or the like
5. Come to the realization that you don't have external storage
6. Knock back 3 more shots of your favorite liquor
7. Buy some external storage
8. Plug in network cable
9. Connect to Internet. Save any info needed for storage
10. Unplug network cable
11. Print all info obtained
12. Plug external storage back in
13. What the...?! Where did this spyware come from?
14. Realize you screwed up the install
15. Knock back 3 or more shots of your favorite liquor
16. Search for the install disks
17. Realize that the computer didn't come with Windows CD
18. Knock back 3 or more shots of your favorite liquor
19. Screw it! Download Gentoo

They should know

They are the ones who made it impossible to delete Internet Exploiter after all.

Re:They should know

Just cause you can't do something doesn't mean it's impossible:

thishouseisclear.bat

echo doh>c:\progra~1\Intern~1\iexplore.exe.new
attrib +r +a +s +h iexplore.exe.new
move c:\progra~1\Intern~1\iexplore.exe c:\progra~1\Intern~1\iexplore.bak
echo doh >c:\progra~1\Intern~1\iexplore.exe
attrib +r +a +s +h c:\progra~1\Intern~1\iexplore.exe

Moments later the fixit wizard will more than likely pop up, hit cancel, and yes. Viola.

Argument for Partitioning

The Windows installer should have a partition editor, and some information about partitioning. It should allow you to easily install Windows on a separate partition from your data.

Then you can keep /home on a separate partition, /var on a sep...

Oh wait.

Re:Argument for Partitioning

There does exist a tool called "linkd" in the Windows 2003 Server resource kit, which allows you to set mount points via the command line.

So you install a system. Use two partitions. Pull the drive. Install 2nd drive on working windows machin. Copy the "Documents and Settings" to the second partition of the newly installed drive. Then use linkd to create a "Documents and Settings" mount point from one partition to the other.

As a semi-serious builder/hobbyist, when I build a system, I use preconfigured sysprep images where I have already done this (the mount point linkage IS copied by programs like ghost that support NTFS5). I can restore a single partition or the whole disk. Either way. I distribute a restore DVD to my customers that can fix their spyware- and virus-hosed Windows installs without killing all the pictures they took with their digital camera etc.

It took me a bit of fiddling to make sure I have the process right, but for the number of times it's saved me two hours' work, I almost want to cry.

Still behind the times

Well, at least Windows is catching up. We've had rootkits on linux forever! :)

Just do what UNIX people do

Boot a clean kernel from removeable, non-writeable media (closed-session CD or write-protected floppy) when doing the rootkit detection. (some details are left to the reader as an exercise)

I am not surprised...

I spent almost two weeks trying to clean the VX2 spyware from a computer that belonged to one of my brothers in law... only to learn the only way to kill this p* of s* is to remove the infected hard disk, plug it into another (uninfected) computer and reformat the whole thing. I kid you not.

I stopped providing "free technical support" to my brothers in law a short while after that episode. And yes, my machines run Linux or OpenBSD.

Re:Further proof

Can you install a linux rootkit by viewing a web page in Mozilla / Konqueror?

Re:Further proof

I don't think a *nix kernel rootkit has ever existed, where a program can modify the kernel and is impossible to remove.

It would have taken all of 30 seconds to google in advance:
http://www.google.com/search?hl=en&q=unix+rootkit+ kernel&btnG=Google+Search [google.com]

--A closed mouth gathers no foot.

Don't get too smug...

...rootkits for Linux are also a bitch to find and get rid of. It's only because we have had this risk for longer that we have good tools to find, remove and otherwise manage the risk... but how many Linux users actually do this?

Probably the same five who spool logs to another sever as well as write-only tape and run everything in chroot I suspect.

Bruce Schneier on the Prototype Detection Tool

Bruce covered the tool in a recent post [schneier.com] on his blog. He says:

This is a really interesting technical report from Microsoft. It describes a clever prototype -- called GhostBuster -- they developed for detecting arbitrary persistent and stealthy software, such as rootkits, Trojans, and software keyloggers. It's a really elegent idea, based on a simple observation: the rootkit must exist on disk to be persistent, but must lie to programs running within the infected OS in order to hide.

Here's how it works: The user has the GhostBuster program on a CD. He sticks the CD in the drive, and from within the (possibly corrupted) OS, the checker program runs: stopping all other user programs, flushing the caches, and then doing a complete checksum of all files on the disk and a scan of any registry keys that could autostart the system, writing out the results to a file on the hard drive.

Then the user is instructed to press the reset button, the CD boots its own OS, and the scan is repeated. Any differences indicate a rootkit or other stealth software, without the need for knowing what particular rootkits are or the proper checksums for the programs installed on disk.

Simple. Clever. Elegant.

In order to fool GhostBuster, the rootkit must 1) detect that such a checking program is running and either not lie to it or change the output as it's written to disk (in the limit this becomes the halting problem for the rootkit designer), 2) integrate into the BIOS rather than the OS (tricky, platform specific, and not always possible), or 3) give up on either being persistent or stealthy. Thus this doesn't eliminate rootkits entirely, but is a pretty mortal blow to persistent rootkits.

Of course, the concept could be adopted for any other operating system as well.

This is a great idea, but there's a huge problem. GhostBuster is only a research prototype, so you can't get a copy. And, even worse, Microsoft has no plans to turn it into a commercial tool.

This is too good an idea to abandon. Microsoft, if you're listening, you should release this tool to the world. Make it public domain. Make it open source, even. It's a great idea, and you deserve credit for coming up with it.

Any other security companies listening? Make and sell one of these. Anyone out there looking for an open source project? Here's a really good one.

Note: I have no idea if Microsoft patented this idea. If they did and they don't release it, shame on them. If they didn't, good for them.

Impossible to clean now

The obscure registry and assinine DLL structure, coupled with incomplete process lists and poorly-defined startup parameters make most spyware impossible to scrape off a system to date.

Here's the link to a free SP2 CD from Microsoft

Install SP2 before you connect a Windows XP machine to the internet.

The last time I connected a fresh Windows XP RTM box to the internet, it was infected with MS Blaster in 6 minutes.

Windows XP Service Pack 2 on CD FREE [microsoft.com]

Windows is catching up to Linux!

I remember attempting to clean systems that had the Linux Rootkit [ossec.net] installed on it in the past. Can't trust results of ps, can't trust results of netstat, can't trust anything.

I can't even imagine having this type of situation on a Windows box. There's just so many more places to hide things and most even technically knowledgable people wouldn't know what to do if their favorite process list application or network connection lister only shows you what the spyware author wants you to see.

If you can even discern there is a problem, re-formatting is your only hope.

This is the Legion of Doom Reporting

Microsoft Warns of Impossible to Clean Spyware

Bizarro: On Bizarro world people like spyware. People no clean from computer. Go now live to Solomon Grundi.

Solomon Grundi: Errrr! Solomon Grundi say Microsoft full of crap. Solomon Grundi crush Microsoft like piece of paper.

Bizzaro: This Legion of Doom reporting. Back to Zonk at Slashdot.

So?

Big deal! Linux has had this for like... ever now!

Oh wait... ;-)

recovering from kernel mode rootkits is hard...

but not impossible. In laymans terms it means you can't trust the OS to provide your user space applications with correct data. Boot into an alternative OS (Knoppix), and you can then run cleanup tools.

It's also possible to use a software hardening tools to prevent changes to the kernel (can't remember the exact company, think the name was "Server-Lock", or something like that).

The real answer is layered security, well managed backup and data protection strategies, and the understanding that no networked PC is immune.

Non infected scanner?

Wouldn't it still be quite possible to scan the system from a non infected source, such as the UBCD4Win [ubcd4win.com]? Its a bootable cd, like knoppix and others, but with a light version of windows XP and a ton of cleaning tools. I use it regularly for cleaning spyware and viruses off thoroughly infected systems.

It's be able to cope with systems having hundreds of virii and such. If you trust it to remove simpler malware, then ingrained rootkits should be a similar problem, for an 'external' system. Not to mention it has all the critical XP system files handy for replacements. A bit easier than the 'nuke it all' aproach, which is beginning to sound like 'reboot and see if the problem goes away'.

In defense of Microsoft....

...Uhhh. Errrr. Ummmm.

Ok. I got nothing.

Hmm

Maybe I'm missing something, but this doesn't seem like anything new. Google for HackerDefender, I'm sure you'll find some relevant links. It intercepts the appropriate system calls to make itself completely invisible: it hides its processes as it's running, it hides the services that start them, etc. I've been seeing it on my employer's Windows servers for quite some time. There are ways to clean it, though they could of course be circumvented as well. The foolproof way to remove it is to boot from a special Windows boot CD and delete the files it uses.

Unless there's something really new and complex going on here, not only is this not new, but IT professionals already have ways of dealing with it. In our case, on a live system with one reboot required. I wouldn't call it minor, certainly (10 minutes of downtime is 10 minutes of downtime), but... hell, if script kiddies have been using this for months and months...

Happened to me 2 days ago.

I was at work, and I'm the only person in our helpdesk to "de-spywarise" the company's PC (I'm the only 2nd level tech analyst). I got a laptop yesterday that was infected with numerous spywares. After removing most of them with HijackThis, Spybot, CWShredder, there was a rogue entry to a file named "elitegfk.exe" in the registry that, as soon as I removed it, came back.

Easy enough I thought, I'll just remove physically the file and the process. But no; the file wasn't ANYWHERE. Yes, I unchecked the "Hide protected system files" checkbox and I was on SHOW HIDDEN FILES, so ALL files were displayed. Heck, a dir /s on the root of the filesystem didn't even work... I thought that it would be possible that the file has another name, renamed itself to that, made its dirty business then renamed itself. I fired up Filemon (from Sysinternal) and sure enough, I see plenty of activity from a process named elitegfk.exe but STILL no sign of the file and/or process. I scanned the registry, and regedit.exe took 2 seconds to complete the scan... !

I was on the verge of reformatting the system when I thought about something: I accessed the laptop through the admin share (\\computer\c$); sure enough, the file was there, sitting quietly sitting in c:\winnt\system32 (Win2k system)...

The spyware prevented its own display through taskmgr, explorer and regedit. Regedt32 didn'T work, I got a virtual memory low error when I tried to scan the registry. The ONLY way I could see the file was through Filemon AND through the file sharing...

I'm guessing next one will palliate to those things by attaching themselves to the most common troubleshootings tools like regmon and attach themselves to the SMB protocol to make sure they can't be displayed through the shares...

This is getting ridiculous. Yes, you'll tell me to switch to Firefox, but we can't; I work in an artistic company with 1000+ PC and non-tech-savyy users, and tons of internal apps that were developped either with .Net or massive ACtiveX and other MS-only stuff, so we can't switch everything to Firefox, and having 2 browsers isn't a viable option either, since most of our users would simply get confused.

Anyway.

Re:Happened to me 2 days ago.

you keep using that word ("can't"). I don't think it means what you think it means.

of course you could switch browsers etc. what you mean is that it is more work than you are willing to do.

just a nitpick on an otherwise interesting story.

but I think it's an important nitpick because things can't keep going the way they are. with all the spam, spyware, viruses etc. there is going to come a point when businesses can't afford to have stupid employees running crap software.

there ARE alternatives available for EVERYONE. adapting will be harder for some than others, but when the options become adapt or die, those using words like "can't" will find themselves on the wrong side of the evolutionary process.

Re:Happened to me 2 days ago.

You say

This is getting ridiculous. Yes, you'll tell me to switch to Firefox, but we can't; I work in an artistic company with 1000+ PC and non-tech-savyy users, and tons of internal apps that were developped either with .Net or massive ACtiveX and other MS-only stuff, so we can't switch everything to Firefox, and having 2 browsers isn't a viable option either, since most of our users would simply get confused.

and I say "That's the price of committing your business to propriatary software and interfaces that are someone elses profit centre."

I know that this doesn't help you in your situation, but it does serve as a cautionary note for those who are not yet in that position, but are considering a move to propriatary software.

Cheer up, though. Once the cost of supporting such a fragile situation exceeds the cost of migrating to a saner environment, you can put the case forth to move to a more secure, more open platform.

Until then, you have my deepest sympathies.

No Clean Boot?

This is new?! It has always been orthodox antivirus doctrine, that you cannot count on being able to reliably clean a compromised system, while you are running that compromised system.

Once you're infected, in order to detect or clean, you have to cold boot from known clean media. How to conveniently do this with Windows, I have no idea. (I used to sometimes check clients' machines by booting from an MS-DOS 6.22 floppy and running F-Prot, but it got harder'n'harder to make that work, for a variety of reasons. It eventually got where the only way I knew to reliably do it, was to physically transplant their hard disk to another Windows machine that was known to be ok. As this was usually impractical, expensive, etc, people stopped asking me for help. ;-)

That's one of the reasons I consider the Windows AV market to mainly be snake-oil. In my limited experience with Windows, all the AV products I've seen, were just applications that the user was expected to run while possibly already compromised. It amused me that people paid for that stuff.

If you're relaying on a scanner to detect and clean stuff after the fact, it's too late and you have no reasonable expectation of the product actually working. The only workable defense is to not get infected in the first place.

Security Levels

It might help if Microsoft took an idea from BSD and made it possible to write-protect critical system files. That way, even if Joe PornMonger downloads worms and viruses while logged in as Administrator, the software would not be able to corrupt the operating system.

I would also add a digital signature check to the bootstrap process, so that critical operating system code wouldn't be loaded unless it was signed by Microsoft.

Universal spyware solution!

Step 1 - Install linux -end

GHOSTBUSTERS!

Damn.. now I'm going to have that theme song in my head all day.. :->


When there's something weird,
and it don't look good
Who ya gonna call?
MI-CRO-SOFT??! (Wait..)

MS needs to release a bootable CD version

Sure, there's Bart's Preinstalled Environment [nu2.nu] bootable-cd-maker but MS really should release a bootable CD of its OSes, complete with cleanup- and other system-maintenance tools, to the community. Heck, I wouldn't even mind typing in my MS-Windows serial number or inserting a floppy that had a key-holding file copied from my hard disk every time I boot. Heck, I'll even pay $5 for the media and give Microsoft my name and address for a tool this useful.

Knoppix rocks but there are some Windows-maintenance things that are much easier in a Windows-booted environment.

I know, right?

I mean, I've been trying to remove "explorer.exe" forever but that damn virus just won't go away.

This proves once more...

how flawed this operating system is.

Flaw #1: Any app can make arbitrary changes to the registry.
Flaw #2: Any app can make arbitrary changes to the system files.
Flaw #3: There is no "safe-mode" for core utilities, that would bypass any hijacking of system calls.

Now can anybody explain to me what was the point of having "system, readonly" attributes, if they can just be turned off?

Bill Gates never wanted to admit it. But this is just proof that Windows is nothing but MS-DOS "on steroids".

Till a few days ago, I thought Linux would be the doom of Microsoft, defeating it like David defeated Goliath. But it turns out.. Goliath is about to die from a genetic anomaly. His very nature gave him a short lifespan.

Oh joy...

Re:This proves once more...

Uh....only apps running as administrator can do these things.

Already in the wild?

One of the computers I support had a very nasty piece of spyware. I am not sure if it was exploiting the same things described by Microsoft, but it had the following symptoms:
1. The process would not show up in task manager
2. The related files would not show up in Explorer
3. The related registry keys did not show up in regedit
4. It some how was being called by Winlogin, so it ran even in safe mode.

The way I detected it was by using several Sysinternals utilities http://www.sysinternals.com/ [sysinternals.com]. I have a script that uses pslist to monitor all processes on the network and this spyware was not smart enough to hide from that. A remote regedit session enabled you to see the related registry files. I had to use BartPE http://www.nu2.nu/pebuilder/ [nu2.nu] to mount the drive and clean out the related files and registry keys.

Beware of trusted computing

For microsoft to make a statment such as this could only mean one thing, they intend to push for trusted computing. Watch for them to lobby the government(s) for this:

trusted computing [smh.com.au]

Enjoy,

Re:Beware of trusted computing

Yes, the "push" has begun ... "this is why computers should only run software from 'trusted', 'licensed' software vendors, and only on 'trusted', 'licensed' hardware", they will say ... the ultimate industry lockout to new potential competitors. And the sad thing is the excuse is a flawed premise; the current widespread and rapidly increasing malware problems are primarily because Windows is such a mess internally. Windows is imploding. And they must have known it was going to happen, over a year ago already, when they suddenly decided to start this massive new focus on security .. they knew their security sucked, they saw this coming, and now they're doing two things: (a) trying to patch Windows fast enough to prevent a total implosion and sudden mass exodus from the platform, and (b) try to capitalise on all the spyware and viruses to push 'trusted' computing platforms in order to gain control of the platform to create artificial barriers to entry for new small competitors.

Don't let users login as either administrators

I think the root of the problem is that most Windows systems (unless centrally managed) are usually setup so that normal users are logged in with elevated priveleges. If they were logged in without supernatural priveleges then the damage done by the spyware, viruses, and trojans, would be limited just to your account and files (e.g. the rest of the system, and certainly the kernel, would be unaffected). So, it seems like the best strategy to fight spyware is to end the current practice of using the administrator account. I am sure that microsoft could even do something to discourage its use.

Not the only way

If the program modifies the Windows kernel in such a way that it is undetectable, couldn't a simple boot CD (running something other than Windows) with a spyware scanner work? Sounds like a potential use of Knoppix, although I'm unaware of any anti-spyware programs for Linux (as spyware is not really a problem on Linux). Something like ClamAV but for spyware would be nice.

Microsoft being inovative again?

"Microsoft researchers have developed a tool, named "Strider Ghostbuster" that can detect rootkits by comparing clean and suspect versions of Windows and looking for differences."

Oh wow! How inovative! Detecting differences by compairing a known good copy with an infected one.... Wow! I wonder if they've appied for the Patent? They've even given it a cute name and everything!

Dark horse anti-spyware apps:

• Linux
• Mac OS X
• BSD

Re:Ok...

Actually, most *NIX rootkits have been intercepting system calls to the kernel and replacing common command tools that might be used to detect and remove them for ages. I haven't heard of one that can avoid detection by the likes of Chkrootkit [freshmeat.net] and Rootkit Hunter [freshmeat.net] yet, other than by being brand new of course. Naturally, that doesn't automatically mean that it's impossible to write one though.

Alternatively....

If you're truly paranoid, you can disable loadable modules, thus preventing a kernel-level rootkit module from being loaded.

steve