WOT WON'T Rated 2 out of 5 stars
Caution: green doesn't always mean safe to browse; I have received security alerts after entering. On one occasion, 57 trojans were detected.Disappointing app.
The add-on isn't a replacement for an antivirus program, it tells you how much other people trust websites. It's possible for a trusted site to be hacked and used to spread malware, but without any details it's difficult to tell if that was what you experienced. Note that you can always report sites on our forum if you believe them to be misrated.