W32.Pahatia.A

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Discovered: May 30, 2006
Updated: February 13, 2007 12:55:50 PM
Type: Worm
Systems Affected: Windows


W32.Pahatia.A is a worm that can spread by copying itself into local folders and mapped network drives, and attempts to restart the compromised computer if certain processes are running.

Antivirus Protection Dates

  • Initial Rapid Release version May 30, 2006
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version May 30, 2006
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date May 31, 2006

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

Writeup By: Chen Yu

Discovered: May 30, 2006
Updated: February 13, 2007 12:55:50 PM
Type: Worm
Systems Affected: Windows


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

  1. Copies itself as the following files:

    • C:\Documents and Settings\All Users\Desktop\My Documents.exe
    • C:\Documents and Settings\All Users\Start Menu\Programs\My Documents.exe
    • C:\Program Files\Microsoft Office\Temp.exe
    • C:\WINDOWS\security\krnl32.bat
    • C:\WINDOWS\system\Aku Bisa Tanpamu.exe
    • C:\WINDOWS\system\Aku Kecewa.exe
    • C:\WINDOWS\system\Dibalas Dengan Dusta.exe
    • C:\WINDOWS\system\ISASS.exe
    • C:\WINDOWS\system\Kau Pikir Kaulah Segalanya.exe
    • C:\WINDOWS\system\LNETINFO.exe
    • C:\WINDOWS\system\mr.abram's.exe
    • C:\WINDOWS\system\Sejauh Mungkin.exe
    • C:\WINDOWS\system\Tak Seperti Dulu.exe
    • C:\WINDOWS\system\Viva Elektro.exe
    • C:\WINDOWS\system32\Patah_0[RANDOM].exe
    • C:\WINDOWS\hkcmd.exe
    • C:\WINDOWS\system.exe

      Note: The file paths are hard-coded in the worm and do not change between operating systems.

  2. Attempts to copy itself as Data [COMPUTER NAME].exe to the following folder and drives:

    • %UserProfile%\My Documents
    • D:
    • E:
    • F:
    • G:
    • H:
    • I:
    • J:
    • K:
    • L:
    • M:
    • N:
    • Z:\

      Note: %UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\[CURRENT USER] (Windows NT/2000/XP).

  3. Searches the subfolder of %UserProfile%\My Documents, and then copies itself as [FOLDER NAME].exe.

  4. Creates the following text file as an infection marker:

    C:\Patah Hati.txt

  5. Copies itself as the following file so that it runs every time Windows starts:

    C:\Documents and Settings\All Users\Start Menu\Programs\Startup\system startup.pif

  6. Adds the values:

    "Patah Hati" = "C:\WINDOWS\system\ISASS.exe"
    "user logon" = "C:\WINDOWS\Help\user logon.exe"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    so that it runs every time Windows starts.

  7. Adds the value:

    "HotKeysCmds" = "C:\WINDOWS\hkcmd.exe"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

    so that it runs every time Windows starts.

  8. Adds the value:

    "Shell" = "Explorer.exe "C:\Program Files\Microsoft Office\Temp.exe""

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

    so that it runs every time Windows starts.

  9. Adds the value:

    "NoFind" = "1"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Policies\Microsoft\CurrentVersion\Policies\Explorer

    to disable access to the Search function.

  10. Adds the values:

    "NoRun" = "1"
    "NoFolderOptions" = "1"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

    to disable access to the Run function and to prevent the user from modifying folder options.

  11. Modifies the values:

    "DisableTaskMgr" = "1"
    "DisableCMD" = "1"
    "DisableRegistryTools" = "1"

    in the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

    to disable the Windows Task Manager, Command prompt, and Registry Editor.

  12. Modifies the values:

    "HideFileExt" = "1"
    "Hidden" = "2"

    in the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

    to hide the file extensions.

  13. Adds the value:

    "RegisteredOrganization" = "mr.abram's"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

  14. Attempts to restart the compromised computer if it detects that the following programs are running:

    • msconfig.exe
    • regedit.exe
    • taskmgr.exe
    • cmd.exe
    • ntvdm.exe
    • setup.exe
    • x-raypc.exe
    • rx box.exe
    • processxp.exe
    • hijackthis.exe
    • sysmech6.exe
    • integrator.exe
    • rstrui.exe
    • mmc.exe
    • winamp.exe

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.

Writeup By: Chen Yu

Discovered: May 30, 2006
Updated: February 13, 2007 12:55:50 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.
  4. Delete any values added to the registry.
  5. Re-enable registry access.
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 and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.


4. To delete the value from the registry
Important: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified subkeys only. For instructions refer to the document: How to make a backup of the Windows registry.
  1. Click Start > Run.
  2. Type regedit
  3. Click OK.

    Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.

  4. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  5. In the right pane, delete the value:

    "Patah Hati" = "C:\WINDOWS\system\ISASS.exe"
    "user logon" = "C:\WINDOWS\Help\user logon.exe"

  6. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

  7. In the right pane, delete the value:

    "HotKeysCmds" = "C:\WINDOWS\hkcmd.exe"

  8. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

  9. In the right pane, modify the value from:

    "Shell" = "Explorer.exe "C:\Program Files\Microsoft Office\Temp.exe""

    to:

    "Shell" = "Explorer.exe"

  10. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Policies\Microsoft\CurrentVersion\Policies\Explorer

  11. In the right pane, delete the value:

    "NoFind" = "1"

  12. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

  13. In the right pane, delete the values:

    "NoRun" = "1"
    "NoFolderOptions" = "1"

  14. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

  15. In the right pane, reset the values to the original values if applicable:

    "DisableTaskMgr" = "1"
    "DisableCMD" = "1"
    "DisableRegistryTools" = "1"

  16. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

  17. In the right pane, reset the values to the original values if applicable:

    "HideFileExt" = "1"
    "Hidden" = "2"

  18. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

  19. In the right pane, delete the value:

    "RegisteredOrganization" = "mr.abram's"

  20. Exit the Registry Editor.

5. To re-enable registry access

If registry access has been disabled, perform the following:
  1. Click Start > Run.
  2. Type:

    Notepad

    and then click OK.

  3. Type, or copy and paste, the following text into the text file:

    REGEDIT4
    [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
    "DisableRegistryTools"=dword:00000000
    [HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\Policies\System]
    "DisableRegistryTools"=dword:00000000

  4. Save the file as C:\Repair.reg.

  5. Click Start > Run.

  6. Type:

    regedit -s C:\repair.reg

    and then click OK.

  7. Follow the step4 in the Removal Instructions: Delete the values that were added to the registry.

Writeup By: Chen Yu