Thursday, August 14, 2008

You Have a Security Problem



If you see the above message popping up on your system, you most certainly do. The creators of Antivirus 2008 have updated their system of delivering fraudulent and inaccurate alerts to users around the world, following up their 2008 money maker with Antivirus 2009:



We've been watching users get slammed by (and TF-protected from) another set of phony codec files, like "codecpack.v.1.0.0.exe", or after its download, "codecpack.v.1.0.0[1].exe". These files kick off the first of the innaccurate warnings like the ones above and download additional content. We're seeing downloads and execution of "AV2009Install_77040502.exe", leading to a slew of phony detections and messages. Don't bother paying to clean up your system with these guys. Just to persist on the system, they often cannot be removed using the standard Windows Add/Remove control applet -- there is no uninstall listing.
And don't believe the pop-up warnings like "Adult content traces found on your PC". They display warnings of adult content that is not present on our lab system as well, listing links to adult sites that do not exist:



Update (8.16.2008): Bill Mullins provides his readers with some great cleanup advice, including SmitFraudFix. You might try SpywareDoctor's cleanup capabilities too.

Update (8.19.2008): Researcher and consultant Dancho Danchev posts an exhaustive list of this group's Rogueware Urls in his "Diverse Portfolio" typo-squating postings.

Monday, August 11, 2008

Malware Writers Love this Blog

Hey, when they add even your blog to their lists of restricted sites on infected machines, you know that you're doing something right.

Our talented colleague Sergei Shevchenko noticed a recent ThreatExpert report in which a not-so-well-detected IRCBot variant is adding the ThreatFire blog url to the hosts files of infected machines, mapping it to the localhost ip. You can see the url in a long list of sites by scrolling down beneath "The HOSTS file was updated with the following URL-to-IP mappings":
127.0.0.1 blog.threatfire.com

This addition to the HOSTS file means that infected users trying to research symptoms of their infected system online won't be able to browse this blog's web pages and find out that the current "msnmessage7.7.exe" file in their c:\windows\system32 directory is causing them a headache.
We suspect that this one is spreading as a part of another IM worm as a message attachment named image_10.zip. When this file is unzipped, its extracted contents have names like "Cle-p.exe".

If you didn't pick up on it, the title of this post is meant to be sarcastic.

Race2Zero Results and Comments

The Race2Zero contest at Defcon added a new voice, the voice of an eager young student from New Zealand, to the conversation regarding the problems of Anti-Virus scanner evasion that has been going on for years. At the base of the effort, the organizer wanted to demonstrate the ease with which AV scanners can be evaded by tweaking already compiled malware and reveal some of the more sophisticated methods that can be used for evasion. It was unclear if he had any experience or skills in the techniques himself. However, by organizing this event, he claimed that as a researcher, he would be able to somehow quantify efforts and results to help with cost/benefit analysis of software defense: "Quantifying how much an attacker must invest to circumvent the defences that a defender has invested in is a key part of being able to evaluate where best to place security spend to gain the most benefit. Race to Zero is one way in which we as researchers can proactively answer these and other questions, while at the same time challenging some of the best minds available in the security community."

He wanted to demonstrate AV shortcomings by providing competing teams with a set of AV-scanner detected malware samples, one after another. The samples would be tweaked by the participants in a way so that the core activity of the software would not be changed but the file would evade on-demand file scanners and remain undetected by 32 scanners. Eventually, one team would race to "zero detection" on all ten samples first. And he wanted it to be fun -- "Reverse engineering and code analysis is fun."

What he succeeded in demonstrating, from what I could tell, is that there are high levels of complexity involved in the setup, preparation, support and understanding of his "competition".
Understanding malware, an environment for working with it, the variety of antivirus products and their uses, PE files, assembly level programming, network traffic, exploits and their delivery vectors, and the relevance of each to AV scanner effectiveness, are all beefy topics that the organizers and their helpers didn't seem to either fully grasp, have the resources to adequately deal with, or both.
Running a handful of command line scanners across a handful of questionably selected (a MS-DOS variant, several widespread worms from several years ago, exploits against Word 2000 without any copies of Word 2000 to test against, etc) malware samples to be modified doesn't really provide the amount of quantifiable results to make large claims for a cost/benefit analysis of security defense and the evaluation of AV scanners. Professional AV test and review groups themselves have a difficult enough time carrying out this sort of evaluation effort with hundreds and sometimes tens of thousands of samples with days or weeks of paid and competent effort, often without the limits of a group of volunteer organizers and speakers attempting the project.

While the subject of the AV evasion black market is always an interesting one for those pushing a behavioral-based technology like ThreatFire, this first "competition" didn't seem to live up to the attention that it received (as the organizer seemed to expect). We'll wait for a technical paper that was proposed to be delivered:
"We hope to be able to give a presentation of findings from Race to Zero at DefCon, a paper has been submitted but a decision on it has not yet been made. Following the contest, when further analysis has been conducted, a technical paper will be publicly released."
Maybe the public paper or an event next year will bring more interesting results with it.

Sunday, August 10, 2008

BlackHat and Defcon 2008

The week of con is over. The best talk of the week must have been Mark Dowd and Alexander Sotirov's "How To Impress Girls With Browser Memory Protection Bypasses". While I'm still not convinced that the girls were impressed with the bypasses, I was. The research was thorough, well done, and very well presented. Their 53 page paper on bypassing all of Microsoft's memory protections through Vista SP1 is up at Mark etc's website here. The techniques are clever and impactful.

The dns tunneling shellcode tricks that I wrote about in the previous post seemed pretty 1980's, so it was nice to follow it up with Mark and Alexander's talk.

We'll post more on the topics tomorrow. I especially liked some of the results and opinions from the Race2Zero contest. In the face of some pretty questionable methodology, the organizer discussed the strong benefits of security in layers, especially the addition of behavioral based protection like ThreatFire.

Wednesday, August 6, 2008

Black Hat 2008

Black Hat Las Vegas 2008. If the latest Dns exploit research performed in part by Dan Kaminsky comes up in casual conversation for you, then these are your people. The ~4,500 nameless researchers and geeks at this conference rush into Ceasar's Palace event halls to hear about recent software security research and reports.
Jeff Moss kicked off the con this morning with a mention that the generous BH sponsors step up to defray rising costs and not to monopolize discussion as a form of advertisement. I'm witnessing that promise realized right now, as Tom Stracener slams one of their very generous sponsors in his presentation. The knowledge is not censored here and flows freely.

One of the topics near and dear to our PC Tools hearts happened to be the focus of Joe Stewart's presentation on reversing Storm titled "Protocols and Encryption of the Storm Botnet". It was somewhat of a Virus Bulletin style presentation, but he added a lot of information regarding offensive techniques for joining the Bot network, disrupting it, and details of his findings about the bot network's communications. It was great stuff.

Also interesting was Jonathan Rom's talk on implementing a javascript based persistent rootkit. While it was somewhat stealth, I don't know that it classified as a rootkit. However, the malcode was fairly well hidden in the plain text file he discussed. And while the design flaw that the code is dependent on for functionality has been patched in Firefox 3 and wasn't as platform dependent as the intro suggested, the idea was well implemented against XP systems in their demo.

Off to another talk on the development and functionality of dns tunneling reverse shellcode.