Windows 7: Microsoft vs. McAfee: How free antivirus outperformed paid

How effective is free antivirus software? I had a chance to see a real, in-the-wild example just this month, and the results were, to put it mildly, unexpected. The bottom line? Microsoft’s free antivirus solution found and removed a threat that two well-known paid products missed. Here are the details. [Update: After I publlished this post, a second example appeared, courtesy of a rogue commenter in the Talkback section. See the results at the end of this post.]

I’ve had Microsoft Security Essentials (MSE) installed on my main working PC for most of the past year. Mostly, I use it for real-time protection. I typically disable the scheduled virus scans on my PCs and instead occasionally do a manual scan just to confirm that nothing out of the ordinary has snuck through. Last month I decided to perform a scan using the Full option. Because I have 2.5 terabytes of hard disk space, with roughly 40% of it in use, I knew the scan would take a long time. So I scheduled it to run while I was out running errands.

When I came back, here’s a snippet of what I found:




MSE had detected several files files that it considered malicious. One was a rigged PDF file (not shown here). The other was a single file in the Java cache folder on this system that contained three separate exploits. Using the information in the MSE history pane, I found the file and uploaded it to Virustotal.com, which is a free service that allows you to scan a suspicious file using 43 separate antivirus engines. The file, identified by a unique hash, had already been analyzed, so I got the results immediately:

McAfee products offer real-time protection using cloud-based Global Threat Intelligence to combat even the most sophisticated threats thus ensuring complete protection and peace of mind.

...
We are rather tired of repeating that VirusTotal was not designed as a tool to perform AV comparative analyses, but as a tool that checks suspicious samples with several AV programs and helps AV labs by forwarding them the malware they failed to detect. Those who use VirusTotal to perform AV comparative analyses should know that they are making many implicit errors in the methodology, the most obvious being:

- VirusTotal AV engines are commandline versions, so depending on the product, they will not behave quite like the desktop versions: for instance, in such cases when desktop solutions use techniques based on behavioral analysis and count on personal firewalls that may decrease entry points and mitigate propagation, etc.

- In VirusTotal desktop-oriented solutions coexist with perimeter-oriented solutions; heuristics in this latter group may be more aggressive and paranoid, since impact of false positives is less visible in the perimeter. It is simply not fair to compare both groups.
...

Quote from Article:
"I’ve had Microsoft Security Essentials (MSE) installed on my main working PC for most of the past year. Mostly, I use it for real-time protection."

So what he is saying is that MSE let the bad stuff in but later found it with a full scan. And that makes it a better product? No AV will stop everything. He must of ran out of ideas to write about with this lame article.

Jim