Worm/Sohanad.AS - Worm

See also

Summary

Full description

Statistics

Virus:	Worm/Sohanad.AS
Date discovered:	20/02/2008
Type:	Worm
In the wild:	Yes
Reported Infections:	Low to medium
Distribution Potential:	Low to medium
Damage Potential:	Low to medium
Static file:	No
File size:	~320.000 Bytes
IVDF version:	7.00.02.163 - Wed, 20 Feb 2008 07:43 (GMT+1)

General Method of propagation:
   • Messenger

Aliases:
   • Kaspersky: IM-Worm.Win32.Sohanad.as
   • F-Secure: IM-Worm.Win32.Sohanad.as
   • Sophos: W32/SillyFDC-AE
   • Eset: Win32/Hakaglan.G worm
   • Bitdefender: Win32.Worm.Sohanad.NBL

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

Side effects:
   • Downloads a file
   • Downloads files
   • Lowers security settings
   • Registry modification

Files It copies itself to the following locations:
   • %SYSDIR%\SCVVHSOT.exe
   • %WINDIR%\SCVVHSOT.exe
   • %SYSDIR%\blastclnnn.exe

The following files are created:

– Non malicious file:
   • %SYSDIR%\setting.ini

– %SYSDIR%\autrun.ini This is a non malicious text file with the following content:
   • [Autorun]
     Open=SCVVHSOT.exe
     Shellexe cute=SCVVHSOT.exe
     Shell\Open\command=SCVVHSOT.exe
     Shell=Open

It tries to download a file:

– The locations are the following:
   • http://www.freewebs.com/setting3/**********
   • http://setting3.9999mb.com/**********
At the time of writing this file was not online for further investigation.

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

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • Yahoo Messengger="%SYSDIR%\SCVVHSOT.exe"

The following registry keys are added in order to load the service after reboot:

– [HKLM\SYSTEM\CurrentControlSet\Services\Schedule]
   • AtTaskMaxHours=dword:00000000

The following registry keys are changed:

Disable Regedit and Task Manager:
– HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
   Old value:
   • DisableTaskMgr=%user defined settings%
   • DisableRegistryTools=%user defined settings%
   New value:
   • DisableTaskMgr=dword:00000001
   • DisableRegistryTools=dword:00000001

Various Explorer settings:
– HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
   Old value:
   • NofolderOptions=%user defined settings%
   New value:
   • NofolderOptions=dword:00000001

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

– Yahoo Messenger

To:
All entries in the contact list.

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:
• UPX

See a brief description here.

Description inserted by Alexander Neth on Fri, 20 Jun 2008 10:42 (GMT+1)
Description updated by Andrei Gherman on Mon, 23 Jun 2008 07:53 (GMT+1)

» About Malware
» About Phishing
» Viruses In the Wild

« back