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Virus:Worm/Koobface.55296D
Date discovered:22/12/2009
Type:Worm
In the wild:Yes
Reported Infections:Low to medium
Distribution Potential:Low to medium
Damage Potential:Low to medium
Static file:Yes
File size:55.296 Bytes
MD5 checksum:ca87c0e3581e0c968e394891af799128
IVDF version:7.10.02.52 - Tuesday, December 22, 2009

 General Aliases:
   •  Panda: W32/Koobface.IW.worm
   •  Eset: Win32/Koobface.NCL
   •  Bitdefender: Worm.Generic.218694


Platforms / OS:
   • Windows 2000
   • Windows XP
   • Windows 2003


Side effects:
   • Downloads a malicious file
   • Drops malicious files
   • Registry modification

 Files It copies itself to the following location:
   • %drive%\windows\mstre26.exe



It overwrites a file.
%WINDIR%\mmsmark3.dat



It deletes the initially executed copy of itself.



It deletes the following files:
   • %malware execution directory%\sd.dat
   • %WINDIR%\dxxdv34567.bat
   • C:\3.reg



The following files are created:

– C:\3.reg This is a non malicious text file with the following content:
   • %code that runs malware%

%malware execution directory%\sd.dat
%WINDIR%\dxxdv34567.bat Furthermore it gets executed after it was fully created. This batch file is used to delete a file.
%drive%\windows\mmsmark3.dat



It tries to download a file:

– The locations are the following:
   • http://dexteracreations.com/**********/?action=%character string%&v=%number%
   • http://www.autobedrijfstolwijk.nl/**********/?action=%character string%&v=%number%
   • http://www.hotelthier.at/**********/?action=%character string%&v=%number%
   • http://mwiapps.co.cc/**********/?action=%character string%&v=%number%
   • http://sauipeswimwear.com/**********/?action=%character string%&v=%number%
   • http://www.bastakigroup.com/**********/?action=%character string%&v=%number%




It tries to executes the following files:

– Filename:
   • %WINDIR%\mstre26.exe


– Filename:
   • cmd /c %WINDIR%\dxxdv34567.bat


– Filename:
   • regedit /s c:\3.reg

 Registry The following registry key is added:

– [HKCR\Mime\Database\Content Type\application/xhtml+xml]
   • "CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}"
   • "Encoding"=hex:08,00,00,00
   • "Extension"=".xml"

 File details Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with a runtime packer.

Description inserted by Petre Galan on Friday, June 18, 2010
Description updated by Petre Galan on Friday, June 18, 2010

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