Scareware hackers exploit McAfee false positive problem

Hackers are exploiting a problem with McAfee’s anti-virus product that has caused hundreds of thousands of computers around the world to repeatedly reboot themselves.

 

The New York Times (and many other news outlets) have reportedon the problems businesses suffered after a detection update issued by McAfee yesterday caused its anti-virus product to mistakenly detect a harmless Windows file, svchost.exe, as “W32/Wecorl.a” and caused computers to become inoperable.

 

To its credit, McAfee is discussing the problem on its online community forum, has apologised, withdrawn the buggy update, and advised customers on how to manually fix the affected computers.

 

But what might be making McAfee’s job of getting reliable information about the false positive problem out to the masses that much harder is that malicious hackers are exploiting the situation.

 

By using blackhat SEO techniques, cybercriminals have managed to get poisoned webpages high in the search rankings if you hunt for information on the McAfee false positive.

If you click on a dangerous link like this then you risk the chance of your computer being hit by a fake anti-virus attack (also known as scareware) which may attempt to con you out of your credit card details or trick you into install malicious code onto your computer.

 

Sophos detects the malware proactively as Mal/FakeAV-BW.

 

The last thing you want to happen if you’re searching for advice on how to fix a problem with the other computers in your company.

 

And it’s not just McAfee’s false alarm problem that these hackers are exploiting. Looking a little deeper at the poisoned domains, allows us to view a cache of hundreds of other pages that this gang have created around a wide range of topics.

Be careful out there folks..

 

 

* Image source: peasap’s Flickr photostream (Creative Commons)

By Graham Cluley, Sophos

 

Tests Show Problems With AV Detections

Dateline: Moscow.

 

Here at a security press conference held by Kaspersky Lab, the company demonstrated how some malware detections are easily triggered by innocuous programs.

 

The problem arises when one vendor detects a threat. Samples are often passed on to other vendors, through multi-scanning services like VirusTotal. The fact that another vendor, particularly a respected one like Kaspersky, detects a threat is enough of a reason to take a serious look at the sample.

 

After suspecting such problems, Kaspersky created a test which demonstrated the phenomenon. They wrote a series of simple and innocuous programs, compiled them, created false detections for them in their engine, and then submitted the files to Virustotal. Only Kaspersky detected the files at this point.

 

But standard procedure with VirusTotal is that if at least one of the products detects a submitted sample, it is submitted to the others who didn’t detect it. The idea is that they can then analyze the file and create their own detection.

 

Instead, what they found was that other companies were creating detections for the false submissions from Kaspersky. The programs create some variables and perform simple mathematical operations on them. They don’t even touch the file system. Kaspersky provided me with the programs and the source code.

 

Click on these to see some of the detections:

• http://www.virustotal.com/analisis/5aee7…1264831301
• http://www.virustotal.com/analisis/0de6d…1264867956
• http://www.virustotal.com/analisis/b2a11…1264867934
• http://www.virustotal.com/analisis/7e79b…1264867923
• http://www.virustotal.com/analisis/0b974…1264831241
• http://www.virustotal.com/analisis/0b974…1264867640

 

But it turns out that the fact that Kaspersky was detecting the threats was not the only reason the others were. The real problems were the aggressive heuristics in the products and that fact that only a static scan was performed.

 

And there is something suspicious about a program that appears to do nothing and then exits. Other vendors I communicated with on the matter said that the behavior was not surprising and that a live on-access detection on a system with their product installed would not be the same. For instance, F-Secure said that “[o]n the end users Windows box, these alerts would show up as a prompt, asking the user whether he really trusts the program. In addition, we have massive whitelist databases in our back-ends, so such prompts would only appear from new, unknown applications.”

 

I suspected that the compiler used to generate the samples might itself be an issue, so I asked Kaspersky about it. They used the mingw crosscompiler, a gcc version for Linux that generates Win32 binaries. It’s possible that the same source code compiled with Microsoft Visual Studio would have generated a different reaction in the anti-malware products, not that it should make a difference. But Kaspersky then creates a “hello world” program with the same compiler and settings and uploaded it to VirusTotal; hours later, even though there were no Kaspersky detections, 2 other products called the sample “suspicious”.

 

This problem is not entirely new; Hispasec Sistemas Lab of Spain, the company that operates VirusTotal, wrote about it a few months ago (original Spanish, Google translation to English). As they point out, the volume of samples coming into company labs is so enormous that the vast majority has to be handled by automated analysis processes, and perhaps they are designed to be a little more paranoid than humans.

 

Kaspersky Lab has written an Analyst’s Diary entry on the issue as well.

 

By Larry Seltzer from PCMag.com