Virus:Worm/Harwig.C
Date discovered:30/08/2005
Type:Worm
In the wild:No
Reported Infections:Low
Distribution Potential:Low to medium
Damage Potential:Low
Static file:Yes
File size:101,446 Bytes
MD5 checksum:070bf77be2f7361d4d52a5a646ae420d
VDF version:6.30.0.222

 General Method of propagation:
   • Messenger


Aliases:
   •  Symantec: W32.Kelvir
   •  Mcafee: W32/Harwig.worm.gen.ba
   •  Kaspersky: IM-Worm.Win32.Harwig.a
   •  TrendMicro: WORM_HARWIG.A
   •  Sophos: W32/Harwig-C
   •  Bitdefender: Worm.Harwig.A


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003


Side effects:
   • Blocks access to certain websites
   • Drops a malicious file
   • Registry modification

 Files It copies itself to the following location:
   • %WINDIR%\abcdefg.exe



The following file is created:

– %WINDIR%\AST.exe Furthermore it gets executed after it was fully created. Further investigation pointed out that this file is malware, too. Detected as: Worm/RBot.72262

 Registry The following registry key is added in order to run the process after reboot:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "FILE"="c:\windows\\abcdefg.exe"



The following registry key is added:

– [HKCU\Software\Microsoft\MSNMessenger]
   • "Server"="messenger.hotmail.com;127.0.0.1:1863"

 Messenger It is spreading via Messenger. The characteristics are described below:

– Windows Live Messenger


Message
The sent message looks like the following:

   • It is you on that picture right?
     Here check it %link%
     OMG! LOL ... Some people put a picture of you online :P, did u know that???


%link%
While the wildcard is the following:
   • http://www.**********database.info/ugly/picture40328.PIF

 Hosts The host file is modified as explained:

– In this case already existing entries remain unmodified.

– Access to the following domain is effectively blocked:
   • messenger.hotmail.com




The modified host file will look like this:


 File details Programming language:
 The malware program was written in MS Visual C++.


Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with the following runtime packer:
   • Morphine 1.4 - 2.7

Description inserted by Iulia Diaconescu on Wednesday, August 31, 2005
Description updated by Iulia Diaconescu on Monday, September 19, 2005

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