Hello FwF,
Well but even with FF we find lately that there are many drive-by installations for these kind of malware (180solutions etc) by misusing the effect of pop-ups that people mistakingly take for MS alerts (click here to continue). Whenever they click they have agreed to an install. I would say, install the golden three (ad-aware, spybot s&d, spyware blaster, have Adblock and NoScript inside the browser, A-squared and you can surf much more relaxed for that matter,
greets,
polonus