Many of us use MSN Messenger to communicate with each other online. Recently, a few contacts unexpectedly sent a file to me without any explanation. When I asked them what it was, there was no response so I closed the window and ignored the file. Good thing I did because it appears that viruses and worms are now clever enough to use instant messaging programs to disseminate themselves.

From ZDNet:

The latest variant of the Bropia worm was discovered on Wednesday evening, Trend Micro said. It infects systems belonging to users of MSN Messenger by sending itself as a picture of a roast chicken with tan lines to all available or online contacts. It also releases a second more dangerous worm, called Agabot.ajc, on the infected computer.

…only open files received through the instant messaging program if they are expected–even if they are from a contact.

Adam Biviano, a senior systems engineer at Trend Micro said this variant of Bropia is the first worm to use instant messaging that has been given a higher-level alert status. It probably won’t be the last, he said.

“Obviously, the popularity of IM itself is starting to gain the attention of the virus writers,” he said, “and they are now using it as a tool.”