Security researchers warned Monday of a new worm, dubbed "Funner," targeting Microsoft Corp.'s MSN Messenger IM (instant messaging)
system.
The worm propagates by sending a copy of itself, disguised as "funny.exe," to contacts found through MSN Messenger. The worm
then makes registry modifications and overwrites entries in the Hosts file, a list used to map IP (Internet Protocol) addresses
to Web sites. Only certain Windows systems, including Windows XP, are vulnerable, according to security researchers.
Researchers currently grade Funner a low threat because of light distribution, though Trend Micro Inc. rates its damage and
distribution potential as "high." Computer Associates International Inc. grades Funner's destructiveness as "medium," while
Symantec Corp. reports fewer than 50 known infections so far. All three vendors have removal instructions posted in security
alerts on their Web sites.