The report, published by secure messaging company Imlogic, highlights a 30 per cent monthly increase in IM viruses and worms since the start of 2005.
"IM viruses and worms are growing exponentially," said Jon Sakoda, CTO at Imlogic. "Virus writers are now shifting the focus of their attack to instant messaging, which is seen as a largely unprotected channel into the enterprise."
In the last 30 days alone Imlogic has released 12 priority alert threat reports, significantly up on previous figures.
The stats were compiled at Imlogic's Threat Center, a joint IM monitoring operation with firms including Symantec, Microsoft and Yahoo. Around 81 per cent of incidents reported to the center involved worms or viruses with around ten per cent of those hijacking IM transfer capability.
The most frequently reported worms were Kelvir, Bropia, and Bizex.
Earlier this month SC reported the surge in IM worms creating a criminal turf war.