Alert level

Trojan:Win32/Vundo.gen!R


Encyclopedia entry
Updated: Jul 24, 2008  |  Published: Jul 07, 2008

Aliases
Not available

Alert Level (?)
Severe

Antimalware protection details
Microsoft recommends that you download the latest definitions to get protected.
Detection last updated:
Definition: 1.45.888.0
Released: Oct 20, 2008 		Detection initially created:
Definition: 1.45.287.0
Released: Oct 07, 2008

Summary

Win32/Vundo is a multiple-component family of programs that deliver 'out of context' pop-up advertisements. They may also download and execute arbitrary files.
Vundo is often distributed as a DLL file and installed on an affected machine as a Browser Helper Object (BHO) without a user's consent. This family uses advanced defensive and stealth techniques to escape detection and to hinder removal.

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Symptoms

System Changes
The following system changes may indicate the presence of Win32/Vundo:
  • Windows Autoupdate service (called 'wuauserv') is disabled
  • The display of 'out of context' advertisements, unrelated to web content being viewed by the affected user.
  • Presence of the following registry entries:
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\aldd
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SysUpd
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{35F7813A-AF74-4474-B1DC-7EE6FB6C43C6}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{39D2FC9B-041C-470E-AE72-F8C001247626}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{44240BB5-BD7D-4D49-A1AA-8AB0F3D3CB44}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{52B1DFC7-AAFC-4362-B103-868B0683C697}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6DD0BC06-4719-4BA3-BEBC-FBAE6A448152}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{7BF451AC-2010-4804-B256-DB2F0A8D9EB6}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{827DC836-DD9F-4A68-A602-5812EB50A834}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{8DBF02DA-4360-4A7E-BEA1-347B87816327}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{AF7FCAFB-9FDB-4F5E-BAC6-68BDEE61D6C6}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{FC148228-87E1-4D00-AC06-58DCAA52A4D1}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{B8B55274-0F9A-41E5-9067-A3539BD9E860}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CBE0D59D-F985-4AC6-8826- FEE957065D42}
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5AEFF965-B1A9-4675-966A-26C2E812AD51}
    HKEY_CLASSES_ROOT\MSEvents.MSEvents
    HKEY_CLASSES_ROOT\MSEvents.MSEvents.1
    HKEY_CLASSES_ROOT\psapianalyzer.psapianalyzer.1
    HKEY_CLASSES_ROOT\psapianalyzer.psapianalyzer
    HKEY_CLASSES_ROOT\MFCOptimizeClass.MFCOptimizeClass.1
    HKEY_CLASSES_ROOT\MFCOptimizeClass.MFCOptimizeClass
    HKEY_CLASSES_ROOT\RawExecAction.RawExecAction
    HKEY_CLASSES_ROOT\RawExecAction.RawExecAction.1
    HKEY_CLASSES_ROOT\iepl.iepl.1
    HKEY_CLASSES_ROOT\iepl.iepl
    HKEY_CLASSES_ROOT\ATLDistrib.ATLDistrib.1
    HKEY_CLASSES_ROOT\ATLDistrib.ATLDistrib
    HKEY_CLASSES_ROOT\WTLHelper.WTLHelper
    HKEY_CLASSES_ROOT\WTLHelper.WTLHelper.1
    HKEY_CLASSES_ROOT\DosSpecFolder.DosSpecFolder
    HKEY_CLASSES_ROOT\DosSpecFolder.DosSpecFolder.1
    HKEY_CLASSES_ROOT\DPCUpdater.DPCUpdater.1
    HKEY_CLASSES_ROOT\DPCUpdater.DPCUpdater
    HKEY_CLASSES_ROOT\ADOUsefulNet.ADOUsefulNet
    HKEY_CLASSES_ROOT\ADOUsefulNet.ADOUsefulNet.1
    HKEY_CLASSES_ROOT\InfoDocReader.InfoDocReader
    HKEY_CLASSES_ROOT\InfoDocReader.InfoDocReader.1
    HKEY_CLASSES_ROOT\ATLEvents.ATLEvents.1
    HKEY_CLASSES_ROOT\ATLEvents.ATLEvents
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\MSEvents.MSEvents
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\MSEvents.MSEvents.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\psapianalyzer.psapianalyzer
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\psapianalyzer.psapianalyzer.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\MFCOptimizeClass.MFCOptimizeClass
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\MFCOptimizeClass.MFCOptimizeClass.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\RawExecAction.RawExecAction
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\RawExecAction.RawExecAction.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\iepl.iepl
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\iepl.iepl.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ATLDistrib.ATLDistrib
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ATLDistrib.ATLDistrib.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WTLHelper.WTLHelper
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WTLHelper.WTLHelper.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\DosSpecFolder.DosSpecFolder
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\DosSpecFolder.DosSpecFolder.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\DPCUpdater.DPCUpdater
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\DPCUpdater.DPCUpdater.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ADOUsefulNet.ADOUsefulNet
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ADOUsefulNet.ADOUsefulNet.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\InfoDocReader.InfoDocReader
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\InfoDocReader.InfoDocReader.1
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ATLEvents.ATLEvents
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ATLEvents.ATLEvents.1

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Technical Information (Analysis)

Win32/Vundo is a multiple-component family of programs that deliver 'out of context' pop-up advertisements. They may also download and execute arbitrary files.
Vundo is often distributed as a DLL file and installed on an affected machine as a Browser Helper Object (BHO) without a user's consent. This family uses advanced defensive and stealth techniques to escape detection and to hinder removal.
 
This variant of Vundo have been observed attempting to disable the Windows Autoupdate service (called 'wuauserv'). This variant may also check if Microsoft’s Malicious Software Removal Tool (mrt.exe) is running and close it if detected.
 
Please see our detailed Win32/Vundo family analysis elsewhere in this encyclopedia for additional information.

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Prevention

Take the following steps to help prevent infection on your system:
  • Enable a firewall on your computer.
  • Get the latest computer updates.
  • Use up-to-date antivirus software.
  • Use caution with attachments and file transfers.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows XP Internet Connection Firewall.
To turn on the Internet Connection Firewall in Windows XP
  1. Click Start, and click Control Panel.
  2. Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
  3. Click Change Windows Firewall Settings.
  4. Select On.
  5. Click OK.
To turn on the Windows Firewall in Windows Vista
  1. Click Start, and click Control Panel.
  2. Click Security.
  3. Click Turn Windows Firewall on or off.
  4. Select On.
  5. Click OK.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. You can use the Automatic Updates feature in Windows XP to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
To turn on Automatic Updates in Windows XP
  1. Click Start, and click Control Panel. 
  2. Click System.
  3. Click Automatic Updates.
  4. Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software that is updated with the latest signature files. Antivirus software is available from several sources. For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.
Use caution with attachments and file transfers
Exercise caution with e-mail and attachments received from unknown sources, or received unexpectedly from known sources.  Use extreme caution when accepting file transfers from known or unknown sources.

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Recovery

Manual removal is not recommended for this threat. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as the Microsoft online scanner (http://safety.live.com). For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.

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