I would guess that most good detection software would also detect any stinkers that a "Portal of Doom" hacker may have added to your system.

Only recently have the usual virus programs started expanding to go after "adware."

I use Norton for viruses, Ad-Aware for the adware, and the free version of ZoneAlarm for port security. There are other good products for these applications. I update constantly, and do frequent (weekly) scans.

Most sources of virus software will also supply removal tools to make sure you aren't still infected. Sometimes for free.

Nothing will make you bulletproof, but like body armor, good defensive software will help a lot.