Need help? Ask the community or hire an expert.
Go to Avira Answers
Virus:Worm/Slenfbot.A.217
Date discovered:20/06/2011
Type:Worm
In the wild:Yes
Reported Infections:Low
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:194.048 Bytes
MD5 checksum:2DC2CAB76D08F88DC964EF09CCFAFC7B
VDF version:7.11.10.37 - Monday, June 20, 2011
IVDF version:7.11.10.37 - Monday, June 20, 2011

 General Aliases:
   •  Kaspersky: Net-Worm.Win32.Kolab.ackc
   •  TrendMicro: WORM_KOLAB.WPR
   •  Microsoft: Worm:Win32/Slenfbot


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003
   • Windows Vista
   • Windows Server 2008
   • Windows 7


Side effects:
   • Drops files
   • Lowers security settings
   • Registry modification

 Files It copies itself to the following location:
   • %SYSDIR%\igfxwp32.exe



It deletes the initially executed copy of itself.



The following file is created:

– C:\cwsandbox\cwsandbox.exe

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

– [HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
   • "Intel Packet Scheduler"="%SYSDIR%\igfxpk32.exe"



It creates the following entries in order to bypass the Windows XP firewall:

– [HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\
   FirewallPolicy\StandardProfile\AuthorizedApplications\List]
   • "%SYSDIR%\igfxwp32.exe"="%SYSDIR%\igfxwp32.exe:*:Enabled:LANMG"

– [HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\
   FirewallPolicy\DomainProfile\AuthorizedApplications\List]
   • "%SYSDIR%\igfxwp32.exe"="%SYSDIR%\igfxwp32.exe:*:Enabled:LANMG"



The following registry keys are added:

– [HKLM\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore]
   • "DisableConfig"=dword:00000001

– [HKLM\SYSTEM\CurrentControlSet\Services\wscsvc]
   • "Start"=dword:00000004

– [HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\
   Layers]
   • "%SYSDIR%\igfxwp32.exe"="DisableNXShowUI"



The following registry keys are changed:

Deactivate Windows Firewall:

– [HKLM\SOFTWARE\Microsoft\Security Center]
   New value:
   • "ProxyBypass"=dword:00000001
   • "AntiVirusOverride"=dword:00000001
   • "AntiVirusDisableNotify"=dword:00000001
   • "FirewallOverride"=dword:00000001
   • "FirewallDisableNotify"=dword:00000001"UNCAsIntranet"=dword:00000001

Various Explorer settings:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\
   Folder\SuperHidden]
   New value:
   • "CheckedValue"=dword:00000001

– [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
   New value:
   • "Hidden"=dword:00000002

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

Description inserted by Andrei Ilie on Tuesday, September 13, 2011
Description updated by Andrei Ivanes on Wednesday, September 21, 2011

Back . . . .