What is SoFunny Worm?
The SoFunny Worm is a Trojan horse with worm capabilities that steals user passwords. This worm was discovered in 2001 and infected AOL users through replication by AOL software. When the worm runs, it will get the user's AOL credentials. The worm may also send infected emails to the user's contacts.
There are two versions of the SoFunny Worm:
W32.SoFunny: Copies itself as \ Windows \ Microsoft420.exe. Applies to Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, and Windows XP. This version uses the attachments “Microsoft420.exe” or “NASTY.exe”.
W95.SoFunny: It copies itself as \ Windows \ Msdos423.exe. It will not run under Windows 2000 / NT. Uses the attachments "Sofunny.exe" and "Love.exe".
The SoFunny Worm is now considered a low risk threat as it can be caught by almost any updated antivirus system.