Can you sue companies that distribute malicious software?

[Björn]

For instance, while I was asleep this morning, my dad downloaded TrusedAntiVirus because it popped up and said he had infected objects on his computer. He was needing a new AntiVirus so he bought it. I quickly uninstalled it, and did virus scans, but upon doing it all Hell was set loose upon his computer.


Now it's basically useless. They gave him a number, and have a website for their "Helpful Product". If he was pursued to do so, could he sue these bastards? I checked the about me on the site and it mentions nothing about it being malware.
The site's www.trustedantivirus.com.