Threat description


Platform: W32
Aliases: Busan, Worm.Win32.Busan


This worm spreads by copying itself to all accessible network resources. The worm is Windows application (C++ PE EXE-file). It's packed by UPX and is around 14kB large.When executed, the worm sends a message through ICQ to the author of the worm, then copies itself to Windows directory with name "files32.sys", and also copies a file "mh32.dll" there. This is a keyboard hooker. Then the worm tries to copy itself with name "auto.exe" to following directory:

C:\WINDOWS\All Users\Start Menu\Program Files\StartUp\  

Because of a bug, this fails. Next the worm copies itself to all accessible network shares.After that the worm registers itself in the system register in a key:

[HKEY_CLASSES_ROOT\exefile\shell\open\command]  @="files32.sys \"%1\" %*"  

This means that when executing any EXE-file the worm will be started.The worm collects information from the local system and tries to send them to the worm writer. This includes addresses, passwords and results of the keyboard snooper.The worm tries download a file "worm31.bmp" from a web-site in the Internet, but this page has been removed and the download fails.[Kaspersky Lab, 13th of April 2003]


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.


More information on scanning and removal options available in your F-Secure product can be found in the Help Center.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.


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