Blackcom

Lost Blackcom is a screamer trojan created by FlashUploads, written in Visual Basic Script.

When activated, it displays a false MSWORD.exe error message, then pauses and displays a binary false error message, followed by Microsoft Sam saying: "CAUTION! A virus has been detected."

Blackcom then displays more bogusfake error messages, one of which is about svchost.exe, pauses, and initiates a system shutdown in 10 seconds, corrupting hall, dll in the system32 directory, rendering Windows unbootable, Furthermore, Blackcom will replace the internet homepage with a YouTube screamer, but it is uncleared what the screamer was.

Link

 * Malware Wiki's Page