The second-quarter increase, the largest hike since Akonix has been recording threats, saw hackers launching 53 new assaults, prompting the Akonix Security Center to issue 23 security policy updates.
The firm said it used its IM malware, SPIM and protocol update system, which automatically pushes updates to customers and blocks worms and viruses in real-time at the network perimeter, to ward off attackers.
''Virus writers are becoming more advanced in their approach to vulnerable IM clients, distributing not only new viruses, but altering current worms to produce more dangerous variants,'' Francis Costello, CTO at Akonix Systems, said in a statement.
''With almost a 400 percent increase in attacks quarter over quarter, IM networks are continuing to get hit by new and growing security threats, and June is a continuation of this trend,'' Costello said.
P2P and IM worm scripters continued the assault primarily with 22 variants of the Kelvir worm, three of the Opanki worm and three of the Oskabot worm, according to Akonix.
Although security features were often in place on the more popular P2P and IM clients, hackers continue to circumvent the protection.
And the increase in attacks isn't likely to slow.
The IMLogic Threat Center reported an increase in attacks through instant messaging clients from 20 in 2004 to 571 in the second quarter of 2005.
''IM usage has reached critical mass, and virus writers have now recognized it as a mostly undefended medium,'' IMlogic CEO and cofounder Francis deSouza said in a statement. ''These are mutating, high-velocity, and invisible to most companies until they hit. All these factors combine to create a serious risk.''
This article was first published on internetnews.com.