Well, I agree there is no guarantee of safe surfing. But anti-virus programs, firewalls, and common sense do help. Any viruses I've had have been caught before doing any damage. Updating your AV regularly is your best defense.
I do kinda doubt this had anything to do with the 7-zip program, but then again I'm no computer expert. Probably just a coincidence. It reminds me of the time I got this spam e-mail that had a trojan attached that was supposed to be a bunch of pictures. The e-mail made reference to (well, described in explicit detail) a - umm, how should I put it - "tryst" between 2 twin brothers and one of the brother's girlfriends. Funny thing was, one of the brother's names and the girlfriend's name in the e-mail were the same as MY brother-in-law and his girlfriend (at the time). And my husband and his brother ARE TWINS! Totally freaked me out! But I went online and investigated a bit and found out it was a hoax e-mail that was going around. HA! It's funny now, but at the time I thought it was really my brother-in-law's girlfriend trying to mess with me (she had "issues").
Anyway, hopefully Ruud can enlighten us a bit next time he checks in.
Lynne