Matcher is an e-mail worm written in Visual Basic. It was first discovered on April 18th, 2001. The worm's file is a PE executable about 29kb long. The worm file is not encrypted or packed. To be run the worm requires MSVBVM60.DLL library to be present in a system.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
When the worm's file is run, it installs itself to system by copying itself as MATCHER.EXE to \Windows\System\ folder and modifying a startup key in the Registry to be always run with Windows. The worm then connects to Outlook, reads e-mail addresses from Address Book and sends itself as MATCHER.EXE to all these addresses. In some cases the worm repeats sending itself every 1 minute. As a result mail servers might be overloaded with worm's messages.
The infected message sent by the worm looks like that:
Subject: Matcher Body: Want to find your love mates!!! Try this its cool... Looks and Attitude Maching to opposite sex. Attachment: Matcher.exe
After that the worm adds a few commands to AUTOEXEC.BAT file that will output a message 'from: Bugger' and pause a system on next startup.
The worm doesn't hide itself and doesn't delete its copies from Sent folder.
To disinfect a system manually, the worm's file MATCHER.EXE should be deleted from \Windows\System\ folder. It is recommended to delete the file from pure DOS as it is locked while Windows is active. You can also use a DOS-based scanner to disinfect your system from pure DOS.
Technical Details: Alexey Podrezov, Katrin Tocheva; F-Secure Corp.; April 18th, 2001