Type Email-Worm
Place of Origin Spain (?)
Platform Microsoft Windows [32-bit]
File Type .EXE
Alias Email-Worm.Win32.Duksten.b

Email-Worm.Win32.Duksten or Duksten is a worm that spreads through email.


Duksten (b) or Protex is a worm virus spreading via the Internet in ZIP files attached to infected emails. The worm itself is a Windows PE EXE file about 10KB in length, encrypted. In infected messages, the attached file is a ZIP archive with the name PROTECT.ZIP where the worm copy ProTecT.exe is stored.

The infected messages have an empty body and the following fields :
From : <boletin@viralert.net>
Subject : ProTeccion TOTAL contra W32/Bugbear (30dias)
Attachment : PROTECT.ZIP
The worm activates from infected emails, only if a user clicks on the attached file. Doing this extracts the .EXE file from the ZIP archive, and runs it. The worm then installs itself to the system and runs its spreading routine and payload.


While installing, the worm copies itself to the Windows system (C:\WINDOWS\SYSTEM) directory with the PrTecTor.exe name and registers this file in the system registry auto-run key :
XRF = %SystemDir%\PrTecTor.exe
The worm then displays a "fake" message:
Su Pc < -_NO_- > fue infectado por el W32/Bugbear
ProTecTor sera operativo durante 30dias pasado ese tiempo debera ReGistrar su copia siguiendo las instrucciones
[ OK ]

It also copies itself to the Windows (C:\WINDOWS) directory under the name regedit.exe and makes a backup copy of the original REGEDIT.EXE file under the name m_regedit.exe.

When a user starts REGEDIT, the worm copy gets control, deletes the worm's "Run" key from system registry, and then executes the original REGEDIT from the "m_regedit.exe" file. When REGEDIT exits, the worm re-installs itself (including in the registry "Run" key).

In short, the worm hides its registry "Run" key when the REGEDIT utility is run because it executes the worm first (causes the worm hides its "Run" key) and then the original REGEDIT utility.


To get victim email addresses, the worm opens the WAB (Windows Address Book) database and reads emails from there. To send infected messages, the worm uses a direct connection to the default SMTP server.

There are several bugs in the email spreading routines, therefore the worm has problems spreading itself to "true" SMTP servers that follow email and transfer standards (RFC standards).

While sending infected emails, the worm also creates the following files in the Windows system directory :
m_WAB.XRF - this file contains victim email(s)
m_Base64.xrf - worm's ZIP file in MIME form
m_prgrm.zip - worm's ZIP file
While storing itself to the ZIP archive the worm uses a "stored" compression method (i.e. "do not compress" method).


Starting from January 1st, 2003, the worm reboots victim machines when logging in.


Run the "m_regedit.exe" file from the Windows directory (this is the original REGEDIT utility).

Delete the worm's registry "Run" key :
XRF = %SystemDir%\PrTecTor.exe
Reboot the machine and remove the following files from the Windows system (C:\WINDOWS\SYSTEM) directory:
Next, go to the Windows (C:\WINDOWS) directory, delete the "regedit.exe" file and then rename the "m_regedit.exe" to "regedit.exe" (doing this restores the original REGEDIT utility) and you are done!

Here's a video about Duksten Windows Worm :

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