W32.Madangel

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Discovered: July 06, 2006
Updated: February 13, 2007 1:01:40 PM
Type: Worm
Systems Affected: Windows


W32.Madangel is a worm that spreads through network shares and attempts to infect .exe files. It also lowers security settings and downloads and executes a remote file.

Antivirus Protection Dates

  • Initial Rapid Release version July 07, 2006
  • Latest Rapid Release version June 22, 2018 revision 025
  • Initial Daily Certified version July 07, 2006
  • Latest Daily Certified version June 23, 2018 revision 002
  • Initial Weekly Certified release date July 12, 2006

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Discovered: July 06, 2006
Updated: February 13, 2007 1:01:40 PM
Type: Worm
Systems Affected: Windows


When W32.Madangel is executed, it performs the following actions:

  1. Creates the following files:

    • %Windir%\rundl132.exe - a copy of W32.Madangel
    • %Windir%\Logo1_.exe - a copy of W32.Madangel
    • %Windir%\vDll.dll - a copy of Downloader

      Note:
    • %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
    • %CurrentFolder% is a variable that refers to the folder where the risk was originally executed.

  2. Checks for the value:

    "auto" = "1"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Soft\DownloadWWW

    and either creates the infection marker or exits if it is found.

  3. Attempts to stop the following service:

    Kingsoft AntiVirus Service

  4. Injects its DLL component, vDll.dll, into either iexplorer.exe or explorer.exe.

  5. Using the DLL component, attempts to download a file from the following location:

    [http://]www.wowchian.com/dl[2 LETTERS[REMOVED]

  6. Searches for .exe files to infect in all the drives from C to Y.

  7. Prepends itself to any .exe files that it locates on the computer.

  8. The worm creates the file _desktop.ini in any any directory it has searched for executable files in. This file has the hidden and system attributes set and it stores the date the worm was executed.

  9. Does not infect .exe files in folders with the following names:

    • system
    • system32
    • windows
    • Documents and Settings
    • System Volume Information
    • Recycled
    • winnt
    • Program Files
    • Windows NT
    • WindowsUpdate
    • Windows Media Player
    • Outlook Express
    • Internet Explorer
    • ComPlus Applications
    • NetMeeting
    • Common Files
    • Messenger
    • Microsoft Office
    • InstallShield Installation Information
    • MSN
    • Microsoft Frontpage
    • Movie Maker
    • MSN Gaming Zone

  10. May send ICMP packets containing the string "Hello,World" to the following IP addresses:

    • 192.168.0.30
    • 192.168.8.1

  11. May also send ICMP packets to IP addresses in the same range as the IP address of the compromised computer.

  12. Attempts to open shared folders with the following names, if any computer responds to the ICMP packet:

    • \\ipc$
    • \\admin$

  13. Tries to open the shared folder using administrator as the username and a blank password. It copies itself to that folder, if it succeeds in opening the shared folder.

  14. Enumerates all the computers and shared folders in the local network. The worm uses a blank username and a blank password to open the shared folders.

  15. Searches for and infects .exe files in the shared folders.


Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

Discovered: July 06, 2006
Updated: February 13, 2007 1:01:40 PM
Type: Worm
Systems Affected: Windows


The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Run a full system scan.
For specific details on each of these steps, read the following instructions.

1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:
Note:
When you are completely finished with the removal procedure and are satisfied that the threat has been removed, reenable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article: Antivirus Tools Cannot Clean Infected Files in the _Restore Folder (Article ID: Q263455).

2. To update the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Running LiveUpdate, which is the easiest way to obtain virus definitions:
    • If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.
    • If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to Virus Definitions (Intelligent Updater).

    The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions. For detailed instructions read the document: How to update virus definition files using the Intelligent Updater.

3. To run a full system scan
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected, follow the instructions displayed by your antivirus program.

Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode . Once you have restarted in Safe mode, run the scan again.

After the files are deleted, restart the computer in Normal mode.