I just got infected with the same Trojan (PWStealer) from a colleague USB memory-stick (which I scanned with BitDefender Internet Security 2009 Scan Tool).
It wasn't detected by BitDefender scanner and passed the BitDefender Real Time Protection infecting explorer.exe and iexplore.exe
Can the BitDefender Boot CD clean this infection at this moment?
...or is there any sure way to remove this infection without reinstalling the entire OS + software setup?