Every program you install on your PC affects the computer's performance and stability, whether you use the app regularly, rarely, or not at all.

More importantly, each time you download a program you're taking a chance that some potentially damaging code has come along for the ride. And as Adam Kujawa points out on his Malwarebytes Unpacked blog, you might not even download the program you intended.

In an October 19 post, Kujawa examined the trend of malware authors disguising their payloads as ads that trick site visitors into clicking on them rather than a legitimate download link by displaying some variation of "Download Now" prominently in the ad.

And would-be downloaders are confused not just by malware disseminators, unfortunately. Kujawa points out that many people attempting to download Malwarebytes' free Anti-Malware antivirus program on CNET's own Download.com end up with a utility I'd never heard of before: ARO 2012, which describes itself as a Windows Registry cleaner.

The free AdBlock Plus add-on (available in a Firefox version and a ... [Read more]