Kelvir.HI, which checks the system settings of an IM client and sends a message in the appropriate language, is the first of its kind, according to researchers at Akonix, a supplier of IM security.
The company rated the worm as a low risk, as did Symantec.
Kelvir.HI spreads through MSN Messager and targets Windows systems, according to Symantec.
The worm downloads a copy of the Spybot worm and sends messages in either English, Spanish, Dutch, French, German, Greek, Swedish, Italian, Portuguese, or Turkish, Akonix researchers said.
In July, Akonix reported a 400 percent increase in IM threats in the second quarter of this year.