Vnunet.com is reporting today about a new mobile virus using an older infection technique to infect Windows Mobile users.

This so-called ‘companion virus’ is attacking users by assuming the identity of an existing file and moving the old file to a different location in your device’s storage. The virus then runs itself when the original file is called, often loading the displaced file after the virus code has been executed.

Researchers at McAfee have examined the virus and are surprised to find this particular infection technique still being used. Researcher Jimmy Shah had this to say:

This was a bit odd since companion viruses used to be more popular in the days of DOS and we haven’t seen too many on newer platforms.

More on the old school virus and how to protect yourself