Our friends and customers from the Netherlands (Surfright.nl) who host their Antispam software with us have just release a free online malware scanner, which detects trojan horses and similar bad software.
Free Malware Analyzer - by Surfright...
If you have a software which you suspect that it does more than it should (eg. a MSN messenger password sniffer) you can upload and check that software with this free online service.
These little fishing malwares are on the rise and you might want to check your software to stay protected.