GeekSnack writes: "Free antivirus software is not hard to come by, but until you test them all out and have a basic understanding of how they work and what are the advantages of a paid antivirus, it might be hard to choose from the hundreds of good offerings."
If you're using any of these four extensions from Avast or AVG on Mozilla Firefox or Chrome, they are collecting way too much data.
Engadget
You'd normally expect antivirus software to improve your web browser's security, but just the opposite was true for AVG until today. The company has fixed an exploit in its protective Chrome extension, WebTuneUp, that would let maliciously-coded websites compromise your PC to a "trivial" degree. It could read your email on the web, for example.
Techspot: Security firm AVG has come under fire from users after revealing its new, “transparent” privacy policy which states that the company can sell search and browser history data to advertisers in order to "make money" from its free antivirus software.
Neither; Avast is the best.
we use AVG, it works for us
There aren't really any decent antivirus programs. AVG is complete garbage, it gets false positives constantly and rarely ever detects any real threats. Avira has a better detection rate but is packed full of popup ads and general annoyances. Avast is slightly better than AVG but still loads of false positives. Getting viruses these days is also very rare unless you do exeedingly stupid things online or still use XP.
Just stick with Windows Firewall/Defender, Noscript, Ad Block Plus and the ABP popup blocker addon. Also avoid the overly nasty porn sites and downloading .exe files from unknown sources.