W32.Novarg.A@mm / W32/Mydoom@MM on the loose

Security firms are currently investigating a new mass-mailing worm. Initial submissions have been received with file extensions of .exe, .pif, .scr, and .zip. This virus tries to spread via email and by copying itself to the shared directory for Kazaa clients if they are present. The body of the message may contain the following variations:

The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.

The message contains Unicode characters and has been sent as a binary attachment.

Mail transaction failed. Partial message is available.

The worm itself is encrypted, and security firms are still working on this. Some companies call it W32/Mydoom@MM and others W32.Novarg.A@mm.

When this file is run it copies itself to the local system with the following filenames:

c:\Program Files\KaZaA\My Shared Folder\activation_crack.scr
%SysDir%\taskmon.exe
(Where %Sysdir% is the Windows System directory, for example C:\WINDOWS\SYSTEM)

It also uses a DLL that it creates in the Windows System directory:

%SysDir%\shimgapi.dll (4,096 bytes)

It creates the following registry entry to hook Windows startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\
CurrentVersion\Run "TaskMon" = %SysDir%\taskmon.exe


When the machine gets infected, the worm will set up a backdoor into the system by opening TCP ports 3127 thru 3198. This will potentially allow a hacker to connect to the machine and utilize it as a proxy to gain access to it's network resources. In addition, the backdoor has the ability to download and execute arbitrary files. The worm will perform a DoS starting on 1 February 2004.