Welcome to the Virus Encyclopedia of Panda Security.
Bugbear.B is dangerous worm that spreads via e-mail and across shared network drives.
It is very easy to become infected by this worm, as it is automatically activated when the message is viewed through Outlook's Preview Pane. It does this by exploiting a vulnerability in Internet Explorer (versions 5.01 and 5.5), which allows e-mail attachments to be automatically run. This vulnerability exploit is known as Exploit/iFrame. However, Bugbear.B does not always exploit this vulnerability in order to affect the computer.
Bugbear.B carries out the following actions in affected computers:
Bugbear.B is a polymorphic worm, which makes it difficult for antivirus programs to detect.
Bugbear.B is difficult to recognize, as it does not display any warnings or messages that indicate that it has infected a computer.
When spreading across shared network drives, Bugbear.B does not check if the directories it is copying itself to are shared printers. Therefore, if it copies itself to one of these directories, the printer will start printing junk characters.