Instant messaging security firms are reporting a dramatic rise in the number of attacks.

Akonix Systems said the month of September holds the dubious distinction of having the most attacks in any month this year at 64.

The September figure follows a disastrous August in which Akonix reported a 200 percent increase in the number of IM vulnerabilities.

FaceTime Security Labs is also reporting a surge in the number of IM threats. It discovered 87 threats on IM and IRC-based networks in September.

"It seems like hackers go on holiday for the summer and come back with fresh attacks in the fall," Chris Boyd, director of malware research at FaceTime Security Labs, told internetnews.com.

Perhaps the hackers spent the summer brushing up on their coding skills, as well. Boyd noted that the complexity of attacks is increasing.

"More interesting than the sheer number of threats, recent discoveries like Pipeline and Heartworm show increasing levels of sophistication on the part of malware creators," Boyd said.

"Pipeline went to great lengths to ensure an installation, with complex download chains and a great focus on the install method, rather than the files themselves."

As with e-mail-borne worms and viruses, threats are now also motivated primarily by financial gain, instead of fame or vandalism.

This article was first published on InternetNews.com. To read the full article, click here.