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Virus:Worm/Autorun.aaew
Date discovered:13/07/2010
Type:Worm
In the wild:Yes
Reported Infections:Low to medium
Distribution Potential:Low to medium
Damage Potential:Low
Static file:Yes
File size:2.048.000 Bytes
MD5 checksum:e0e232a01f00ff2a69d94822ed24f483
IVDF version:7.10.09.77 - Tuesday, July 13, 2010

 General Method of propagation:
   • Autorun feature


Aliases:
   •  Mcafee: W32/Autorun.worm.f virus
   •  Bitdefender: Worm.Autoit.B
   •  Panda: W32/Sohanat.IZ
   •  Eset: Win32/Sohanad.NFL


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


Side effects:
   • Drops malicious files
   • Registry modification

 Files It copies itself to the following locations:
   • %WINDIR%\regsvr.exe
   • %SYSDIR%\svchost .exe
   • %SYSDIR%\regsvr.exe
   • %drive%\regsvr.exe



The following files are created:

%SYSDIR%\setup.ini
%drive%\autorun.inf This is a non malicious text file with the following content:
   • %code that runs malware%

%SYSDIR%\28463\svchost.001



It tries to executes the following files:

– Filename:
   • %SYSDIR%\cmd.exe /C AT /delete /yes


– Filename:
   • AT /delete /yes


– Filename:
   • %SYSDIR%\cmd.exe /C AT 09:00 /interactive /EVERY:m,t,w,th,f,s,su %SYSDIR%\svchost .exe


– Filename:
   • AT 09:00 /interactive /EVERY:m,t,w,th,f,s,su %SYSDIR%\svchost .exe

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

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • "Msn Messsenger"="%SYSDIR%\regsvr.exe"



The following registry keys are added:

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System]
   • "DisableRegistryTools"=dword:0x00000001
   • "DisableTaskMgr"=dword:0x00000000

– [HKLM\SYSTEM\CurrentControlSet\Services\Schedule]
   • "AtTaskMaxHours"=dword:0x00000000

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
   • "NofolderOptions"=dword:0x00000000

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\
   WorkgroupCrawler\Shares]
   • "shared"="\New Folder .exe"



The following registry key is changed:

– [HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
   New value:
   • "Shell"="Explorer.exe regsvr.exe"

 Miscellaneous  Checks for an internet connection by contacting the following web sites:
   • http://yahoo.com/setting.xls
   • http://www.yahoo.com/setting.xls
   • http://yahoo.com/setting.doc
   • http://www.yahoo.com/setting.doc

 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 Tuesday, July 27, 2010
Description updated by Petre Galan on Monday, August 2, 2010

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