Once again the Lab’s virus wall statistics for last month were very similar to the previous month. The virus wall detected and eradicated a total of 110,089 worms and viruses (almost all of which target Windows systems), up slightly from 106,157 worms and viruses the previous month.

The Netsky.P worm once again led all others with 58,943 copies identified and deleted (down slightly from 59,758 the month before). Netsky.D placed second again with 6,902 copies (down slightly from last month) found and eradicated, followed once more by the Beagle.W (also known as Bagle.Z) worm with 4,491 instances identified and eradicated (also down slightly from last month). All three are Windows-targeting mass-mailing worms, copies of which arrive in the form of attachments in messages with a wide variety of subject names.

An interesting new worm on the scene last month was the Funner worm. It targets Microsoft's MSN Messenger Instant Messenger, propagating by sending a copy of itself in the form of a file named "funny.exe" to every MSN Messenger contact it discovers. The worm changes the Registry and overwrites entries in an important file (the "hosts" file) used to associate IP addresses with host names. Experts believe that one reason that this somewhat destructive worm did not spread more is that it infects only a few types of Windows systems, of which Windows XP is the most vulnerable.

Remember that in spite of the Lab’s excellent virus wall, the responsibility for keeping your system virus- and worm-free belongs to each Lab user. Run anti-virus software (available for free online) on every Windows and Macintosh system, keep this software updated daily, and avoid opening attachments that you are not expecting.