Trojans etc. that steal passwords

I recently had a spyware (and possibly virus as well) problem with my computer where my desktop was changed and it said something like “your computer is infected etc.” and a program opened up that asked to buy a spyware removal product. I started up the computer in safe mode and then ran spybot and it removed a bunch of problems. I also ran an online antivirus scan and it removed a few things. When I started up the computer in normal mode everything was absolutely fine except for 2 things.

I have 2 entries that keep on reappearing in my spybot scan every time I restart the computer. They are “Win32.TDSS.rtk” and “Microsoft.WindowsSecurityCenter_disabled”. Before I consider taking steps to permanently remove them, I just want to know if they can steal passwords. If they can’t, then it’s really not worth bothering with them because I can’t see any symptoms. Also, could there be other things on my computer that spybot and antiviruses can’t detect that could be causes problems even though there are no symptoms now, or did the spybot and virus scans removing everything that is problematic?

Thanks.

Jam it back in, in the dark.