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Virus:Worm/Conficker.L
Date discovered:08/07/2009
Type:Worm
In the wild:Yes
Reported Infections:Low to medium
Distribution Potential:Medium
Damage Potential:Low to medium
Static file:Yes
File size:137.240 Bytes
MD5 checksum:7993910f4e91016fe85d31583745953a
IVDF version:7.01.04.200 - Wednesday, July 8, 2009

 General Methods of propagation:
   • Autorun feature
   • Local network


Aliases:
   •  Mcafee: W32/Conficker.worm.gen.a
   •  Sophos: Mal/Conficker-A
   •  Panda: W32/Conficker.C.worm


Platforms / OS:
   • Windows 2000
   • Windows XP
   • Windows 2003
   • Windows Vista
   • Windows Server 2008
   • Windows 7


Side effects:
   • Drops malicious files
   • Lowers security settings
   • Registry modification
   • Makes use of software vulnerability
      •  CVE-2007-1204
      •  MS07-019

 Files It copies itself to the following locations:
   • %SYSDIR%\qepdjla.dll
   • %drive%\RECYCLER\%CLSID%\qepdjla.dll



It deletes the initially executed copy of itself.



The following file is created:

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




It tries to execute the following file:

– Filename:
   • explorer C:

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

– [HKLM\SYSTEM\CurrentControlSet\Services\ufvxwft]
   • "Description"="Enables a user to configure and schedule automated tasks on this computer. If this service is stopped, these tasks will not be run at their scheduled times. If this service is disabled, any services that explicitly depend on it will fail to start."
   • "DisplayName"="Universal Installer"
   • "ErrorControl"=dword:0x00000000
   • "ImagePath"="%SystemRoot%\system32\svchost.exe -k netsvcs"
   • "ObjectName"="LocalSystem"
   • "Start"=dword:0x00000002
   • "Type"=dword:0x00000020

–  [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • Windows Defender



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

– [HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\
   FirewallPolicy\StandardProfile\GloballyOpenPorts\List]
   • "8182:TCP"="8182:TCP:*:Enabled:opijcn"



The following registry key is added:

– [HKLM\SYSTEM\CurrentControlSet\Services\ufvxwft\Parameters]
   • "ServiceDll"="%SYSDIR%\qepdjla.dll"



The following registry keys are changed:

– [HKEY_USERS\.DEFAULT\Software\Microsoft\Windows NT\CurrentVersion\
   Winlogon]
   New value:
   • "ParseAutoexec"="1"

– [HKCU\Software\Microsoft\Internet Explorer\Toolbar]
   New value:
   • "Locked"=dword:0x00000001

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
   New value:
   • "DontPrettyPath"=dword:0x00000000
   • "Filter"=dword:0x00000000
   • "Hidden"=dword:0x00000002
   • "HideFileExt"=dword:0x00000000
   • "HideIcons"=dword:0x00000000
   • "MapNetDrvBtn"=dword:0x00000001
   • "SeparateProcess"=dword:0x00000001
   • "ShowCompColor"=dword:0x00000001
   • "ShowInfoTip"=dword:0x00000000
   • "SuperHidden"=dword:0x00000000
   • "WebView"=dword:0x00000000

– [HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost]
   New value:
   • "netsvcs"="6to4"

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\
   Folder\Hidden\SHOWALL]
   New value:
   • "CheckedValue"=dword:0x00000000

 Network Infection In order to ensure its propagation the malware attemps to connect to other machines as described below.


Exploit:
It makes use of the following Exploits:
– MS04-007 (ASN.1 Vulnerability)
– MS05-039 (Vulnerability in Plug and Play)
– MS06-040 (Vulnerability in Server Service)


Remote execution:
–It attempts to schedule a remote execution of the malware, on the newly infected machine. Therefore it uses the NetScheduleJobAdd function.

 Injection – It injects a backdoor routine into a process.

    Process name:
   • svchost.exe


 Miscellaneous  Checks for an internet connection by contacting the following web sites:
   • http://www.whatismyip.org
   • http://checkip.dyndns.org


Mutex:
It creates the following Mutexes:
   • vcxhnoiftekm
   • dvkwjdesgb
   • npszuxsqlrl

 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, December 3, 2010
Description updated by Andrei Ivanes on Tuesday, June 5, 2012

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