Backdoor.Haxdoor.R

SUMMARY

Backdoor.Haxdoor.R is a Trojan horse program that opens a back door on the compromised computer and allows a remote attacker to have unauthorized access.

Protection

• Virus Definitions (LiveUpdate™ Daily) October 10, 2006
• Virus Definitions (LiveUpdate™ Weekly) October 11, 2006
• Virus Definitions (Intelligent Updater) October 10, 2006
• Virus Definitions (LiveUpdate™ Plus) October 10, 2006

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload: Opens a back door on the compromised computer.

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

Once executed, Backdoor.Haxdoor.R performs the following actions:

1. Drops the following files:
   
   
   • %System%ydsvgd.dll
   • %System%ydsvgd.sys
   • %System%ycsvgd.sys
   • %System%qo.dll
   • %System%qo.sys
     
     Note: %System% is a variable that refers to the System folder. By default this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).
     
     
2. Creates the following files to store stolen information:
   
   
   • %System%shsvga.bin
   • %System%gsvga.bin
   • %System%mnssvgas.bin
   • %System%lps.dat
   • %System% tsvga.dat
   • %System% 001f.exd
   • %System%wagfola4w.dat
   • %System%kgctini.dat
     
     
3. Hides all of the above files using a rootkit.
   
   
4. Creates the following services:
   
   
   • ycsvgd
   • ydsvgd
     
     
5. Creates the following registry subkeys, which are related to the above services:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesycsvgd
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesydsvgd
   
   
6. Creates the following registry subkey:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetEnumRoot
   LEGACY_YCSVGD
   
   
7. Creates the following registry subkey on computers running Windows NT/2000/XP so that it is executed every time Windows starts:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows NTCurrentVersionWinlogonNotifyydsvgd
   
   
8. Creates the following registry subkeys so that it runs in safe mode:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootMinimalycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootMinimalycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootNetworkycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootNetworkycsvgd.sys
   
   
9. Deletes the value:
   
   "Start" = "[NUMBER]"
   
   from the registry subkey:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServiceswscsvc
   
   to disable the Windows Security Center.
   
   
10. Adds the value:
    
    "EnforceWriteProtection" = "0"
    
    to the registry subkey:
    
    HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management
    
    to disable Microsoft DEP write protection.
    
    
11. Hides its presence by injecting the following file into the Explorer.exe:
    
    %System%ydsvgd.dll
    
    
12. Opens a back door on a random TCP port. The remote attacker can then perform the following actions on the compromised computer:
    
    
    • Download files
    • Execute programs
    • Control the device driver of the rootkit
    • Steal passwords stored in Protected Storage
    • Steal cached passwords by calling WNetEnumCachedPasswords API
    • Steal the Miranda IM password
    • Gather dialup connection information
    • Check if WebMoney application is installed on the compromised computer
    • Steal ICQ passwords
    • Log keystrokes
      
      
13. Sends information, such as the port used by the back door, Windows version information, etc, to an attacker by sending a query to the following URL:
    
    [http://]www.grci.info/bsrv[REMOVED]
    
    
14. Sends an email containing the stolen information to a predetermined email address.

Recommendations

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

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. 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.

REMOVAL

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

1. Restart the computer using the Windows Recovery Console.
2. Disable System Restore (Windows Me/XP).
3. Update the virus definitions.
4. Run a full system scan.
5. Delete any values added to the registry.
   

For specific details on each of these steps, read the following instructions.

1. To restart the computer using the Windows Recovery Console
To remove this threat it is necessary to restart the computer and run the Windows Recovery Console. For full details on how to do this please read the Microsoft Knowledge Base article, How to install and use the Recovery Console in Windows XP.

1. Insert the Windows XP CD-ROM into the CD-ROM drive.
2. Restart the computer from the CD-ROM drive.
3. Press R to start the Recovery Console when the "Welcome to Setup" screen appears.
4. Select the installation that you want to access from the Recovery Console.
5. Enter the administrator password and press Enter.
6. Type cd system32
7. Press Enter
8. Type del ydsvgd.dll
9. Press Enter
10. Type del ydsvgd.sys
11. Press Enter
12. Type del ycsvgd.sys
13. Press Enter
14. Type del qo.dll
15. Press Enter
16. Type del qo.sys
17. Press Enter
18. Type del shsvga.bin
19. Press Enter
20. Type del gsvga.bin
21. Press Enter
22. Type del mnssvgas.bin
23. Press Enter
24. Type del lps.dat
25. Press Enter
26. Type del ttsvga.dat
27. Press Enter
28. Type del t001f.exd
29. Press Enter
30. Type del wagfola4w.dat
31. Press Enter
32. Type exit
33. Press Enter. The computer will now restart automatically.
    
    

2. 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:

• How to disable or enable Windows Me System Restore
• How to turn off or turn on Windows XP System Restore

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).

3. 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.

4. To run a full system scan

1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
   • For Norton AntiVirus consumer products: Read the document: How to configure Norton AntiVirus to scan all files.
   • For Symantec AntiVirus Enterprise products: Read the document: How to verify that a Symantec Corporate antivirus product is set to scan all 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.


5. 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 and delete the subkeys:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesycsvgd
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesydsvgd
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetEnum
   RootLEGACY_YCSVGD
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows NT
   CurrentVersionWinlogonNotifyydsvgd
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootMinimalycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootMinimalycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootNetworkycsvgd.sys
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControl
   SafeBootNetworkycsvgd.sys
   
   
5. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServiceswscsvc
   
   
6. In the right pane, reset the value:
   
   "Start" = "[NUMBER]"
   
   
7. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management
   
   
8. In the right pane, reset the value:
   
   "EnforceWriteProtection" = "0"
   
   
9. Exit the Registry Editor.