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  3. Trojan.Flush.A

Trojan.Flush.A - Removal

Risk Level 1: Very Low

Discovered:
March 4, 2005
Updated:
February 13, 2007 12:34:41 PM
Type:
Trojan Horse
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

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 and delete all the files detected as Trojan.Flush.A.
  4. Delete the value that was added to the registry.
  5. Delete the entries that was added to the RAS phone-book file.
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, re-enable 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: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • 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 the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. To scan for and delete the infected files
  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 as infected with Trojan.Flush.A, click Delete.

    Note:
    If your Symantec antivirus product reports that it cannot delete an infected file, Windows may be using the file. To fix 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 section 4.
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. Read the document, "How to make a backup of the Windows registry," for instructions.
  1. Click Start > Run.
  2. Type regedit

    Then click OK.

  3. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip
    \Parameters\Adapters

  4. In the right pane, delete the value:

    "NameServer" = "69.50.176.196,195.225.176.37"

  5. Navigate to the subkey:

    HKEY_CURRENT_USER\RemoteAccess\Profile

  6. In the right pane, delete the value:

    "IP" = "02,00,00,00,00,00,00,00,c4,b0,32,45,25,b0,e1,c3,00,00,00,00,00,00,00,00,00,00,00,00"

  7. Exit the Registry Editor.


5. To delete the added entries from the RAS phone-book file

Note: The location of the RAS phone-book file rasphone.pbk may vary and some computers may not have this file. For example, if the file exists in Windows XP, it is usually located in the C:\Documents and Settings\All Users\Application Data\Microsoft\Network\Connections\Pbk folder.

Follow the instructions for your operating system:
  • Windows 95/98/Me/NT/2000
    1. Click Start, point to Find or Search, and then click Files or Folders.
    2. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
    3. In the "Named" or "Search for..." box, type:

      rasphone.pbk
    4. Click Find Now or Search Now.
    5. If you find rasphone.pbk, right-click the file, and then click "Open With."
    6. Deselect the "Always use this program to open this program" check box.
    7. Scroll through the list of programs and double-click Notepad.
    8. When the file opens, delete the entries below:


      "IpDnsAddress=69.50.176.196"
      "IpDns2Address=192.225.176.37"
      "IpNameAssign=2"

    9. Close Notepad and save your changes when prompted.

  • Windows XP
    1. Click Start, and then click Search.
    2. Click All files and folders.
    3. In the "All or part of the file name" box, type:

      rasphone.pbk
    4. Verify that "Look in" is set to "Local Hard Drives" or to (C:).
    5. Click "More advanced options."
    6. Check "Search system folders."
    7. Check "Search subfolders."
    8. Click Search.
    9. Click Find Now or Search Now.
    10. If you find rasphone.pbk file, right-click the file, and then click "Open With."
    11. Deselect the "Always use this program to open this program" check box.
    12. Scroll through the list of programs and double-click Notepad.
    13. When the file opens, delete the entries below:

      "IpDnsAddress=69.50.176.196"
      "IpDns2Address=192.225.176.37"
      "IpNameAssign=2"

    14. Close Notepad and save your changes when prompted.


Writeup By: John Canavan

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