MSN-Yahoo! IM love-in could spread worms

The planned bridge between MSN Messenger and Yahoo! Messenger has one drawback, experts warn: it could act as a conduit for a massive IM worm outbreak.

On Wednesday, Microsoft and Yahoo! announced that they would make their instant-messaging services interoperable. By the middle of next year, users of both are expected to be able to exchange instant messages, see if their contacts are online, share emoticons, add friends from either service and make PC-to-PC voice calls.

But the partnership has a flipside, an instant-messaging security expert said. Jon Sakoda, chief technology officer at messaging security company IMlogic, said: "As Microsoft, Yahoo! and others connect their global IM networks, IM worms will spread faster and attack a larger population of end-users."

Instant-messaging service users are being hit with more worm and malicious code attacks than ever before. The number of threats detected for IM and peer-to-peer networks rose 3,295 per cent in the third quarter of 2005, compared with last year, according to a recent IMlogic report. The company sells products to help businesses protect themselves against IM-borne pests, in competition with companies such as Akonix Systems.

An Akonix spokesman said: "A worm could proliferate further and faster on the combined network. The need for security rises as we now have a much bigger network and much more usage."

The alliance could turn up the heat on people using Yahoo! IM. Microsoft's network is the most popular object of IM worms, as 62 per cent of attacks in the third quarter this year were aimed at MSN Messenger or Windows Messenger, IMlogic said. In the same period, only seven per cent of IM worms went after Yahoo! Messenger.

IMlogic's Sakoda said: "Worms that are traditionally targeting MSN will also target the Yahoo! users."

AOL Instant Messenger dominates the instant-messaging arena in the US, tallying 51.5 million users in September, according to research firm Nielsen/NetRatings. That compares with 27.3 million for MSN and 21.9 million for Yahoo!.

Providing a secure IM service is top priority at Yahoo! and Microsoft, according to a Yahoo! spokeswoman. "This priority is certainly extending to the interoperability between our two communities," she said. "We will certainly continue to innovate together and leverage our collective best practices to keep IM safe and secure."

Yahoo!'s statement was echoed by Microsoft. Brooke Richardson, a lead product manager for MSN at Microsoft, said in an emailed statement: "Microsoft and Yahoo! share a commitment to deliver IM interoperability while keeping consumer security, safety and privacy top of mind."

Joris Evers writes for CNET News.com