Worm attacks over instant-messaging networks increased 1700 percent in 2005, while e-mail spam remained constant at about 75 percent to 80 percent of all messages sent, according to an annual report issued by messaging security service provider Postini on Monday.
Postini generated its 2005 report by analyzing the messages that come through its global data centers where it filters customers' messages for spam, viruses, and other malware. These centers scan a billion messages a day on average, according to Andrew Lochart, Postini's senior director of marketing.
The findings related to instant messaging, which came from the threat center of Postini partner IM Logic, showed that MSN Messenger took the brunt of IM attacks in 2005, accounting for 57 percent of all worms detected. AOL's IM service accounted for 34 percent of the attacks, and Yahoo's IM network was home to 9 percent, the report says.
"Hackers have discovered IM, it's the new playground for them," says Lochart, adding that as IM service providers strike agreements to pass each other's message traffic back and forth, worms will spread back and forth as well.
Postini's report also showed that the proportion of spam to legitimate mail dipped slightly towards the end of 2005, mainly because of an increase in virus- and phish-laden e-mails.
Discounted drugs and software topped the spam categories in 2005 at 28 percent.
The company's e-mail security service found 2.5 percent of all blocked inbound messages contained viruses, and nearly 2 percent of outbound e-mail -- from companies that subscribe to Postini's outbound filtering service as well -- contained viruses.