This threat is detected with the 4127 DATs, or higher, with various names. The 4215 DATs, and higher, detect it as Bat/a. This is an IRC spreading worm and intended mass mailer. It is intended to arrive in an email message containing the following information, but due to bugs the mailing routine fails: Subject: Upgrade to Windows XP Body: Good news from Microsoft. Click the attachment for your FREE Windows XP. Upgrade to Windows XP now. Attachment: UpgradeToWindowsXP.bat When run, the batch file creates several other files.