Just How Prevalent are Viruses?

One of the questions we're most often asked is,

C'mon... do I really need antivirus software? Doesn't it just slow your PC down anyway?

Our answer? "Yes, and no, not really¹."

It turns out the need may be even more acute than we believed, as One in every 20 Windows PCs whose users turned to Microsoft for cleanup help were infected with malware, and according to a Computer World piece, "New malware scanner finds 5% of Windows PCs infected, that's according to Microsoft's own data on their Microsoft Safety Sacnner.

Yowza.

Here's the first kicker: that only counts the number of folks who used the Microsoft tool, and doesn't count those who:

1. downloaded the tool on one PC and moved malware from a second (or third or other computer)
2. took their computer to Best Buy or their local PC repair shop
3. had their geek niece/nephew/neighbor fix their computer
4. consulted search engines for to repair their PC on their own
5. installed antivirus software on their own
6. gave up and purchased a new PC

Here are a couple of other interesting tidbits from the Computer World article,

On average, each of the infected PCs hosted 3.5 threats, which Microsoft defined as either actual malware or clues that a successful attack had been launched against the machine.

This is almost as interesting to me as the 1-in-20 stat. What this seems to show is that when you run your PC without antivirus software, chances are when it gets hit, it gets really hit.

Why?

Certainly some portion of those may be multiple infections arising from the same initial infection, but the bulk are no doubt infections happening at different times and perhaps even via different infection techniques.

This means when you lack protection, it's not that you get infected once, and you're done. On the contrary. Having one virus doesn't mean you can't get more. In fact, you'll probably have three-and-a-half.

Another important tidbit: the majority of the infections came via Java exploits, interesting most of all because they

Given that we ourselves test every product we review with live viruses and all sorts of other malware, we know that no antivirus software is perfect. The bottom line is though that antivirus software does give you a significant advantage and help keep your PC protected and virus free.

¹Yes, crappy antivirus software slows your machine down. Definitely. The best antivirus software, doesn't.