W32.Qakbot Permission Reset Tool

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Discovered: April 20, 2011
Type: Removal Information

This tool is designed to restore the access control list (ACL) of your Symantec security product altered by W32.Qakbot .

Note: This tool does not remove infections of W32.Qakbot from a compromised computer.

How to download and run the tool

Important: You must have administrative rights to run this tool on Windows NT 4.0, Windows 2000, Windows XP., Windows 2003, Windows Vista, Windows 2008, or Windows 7.

Follow these steps to download and run the tool:

  1. Download the W32.Qakbot Permission Reset Tool file from: http://www.symantec.com/content/en/us/global/removal_tool/threat_writeups/FixAcl.exe.
  2. Save the file to a convenient location, such as your Windows desktop.
  3. Optional: To check the authenticity of the digital signature, refer to the "Digital signature" section later in this writeup.

    Note: If you are sure that you are downloading this tool from the Security Response Web site, you can skip this step. If you are not sure, or are a network administrator and need to authenticate the files before deployment, follow the steps in the "Digital signature" section before proceeding with step 4.

  4. Close all the running programs.
  5. If you are on a network or if you have a full-time connection to the Internet, disconnect the computer from the network and the Internet.
  6. If you are running Windows Me or XP, turn off System Restore. 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

  7. Locate the file that you just downloaded.
  8. Double-click the FixAcl.exe file to start the tool.
  9. Click Start to begin the process, and then allow the tool to run.

    Note: If you have any problems when you run the tool, or it does not appear to remove the threat, restart the computer in safe mode and run the tool again.

  10. Restart the computer.
  11. If you are running Windows Me/XP, then reenable System Restore.
  12. If you are on a network or if you have a full-time connection to the Internet, reconnect the computer to the network or to the Internet connection.
  13. Run LiveUpdate to make sure that you are using the most current virus definitions.

When the tool has finished running, you will see the following message:

What the tool does
The tool fixes permissions on Symantec folders affected by W32.Qakbot.


The following switches are designed for use by network administrators:
/HELP, /H, /?
Displays the help message.
Enables the silent mode.

Digital signature
For security purposes, the removal tool is digitally signed. Symantec recommends that you use only copies of the removal tool that have been directly downloaded from the Symantec Security Response Web site.

If you are not sure, or are a network administrator and need to authenticate files before deployment, you should check the authenticity of the digital signature.

Follow these steps:
  1. Go to http://www.wmsoftware.com/free.htm.
  2. Download and save the Chktrust.exe file to the same folder in which you saved the removal tool.

    Note: Most of the following steps are done at a command prompt. If you downloaded the tool to the Windows desktop, it will be easier if you first move the tool to the root of the C drive. Then save the Chktrust.exe file to the root of C as well.

    (Step 3 to assume that both the removal tool and Chktrust.exe are in the root of the C drive.)

  3. Click Start > Run.
  4. Type one of the following:

    Windows NT/2000/XP/Vista/7:

  5. Click OK.
  6. In the command window, type the following, pressing Enter after typing each line:

    cd downloads
    chktrust -i FixAcl.exe

  7. You should see one of the following messages, depending on your operating system:

    Windows XP SP2:
    The Trust Validation Utility window will appear.

    Under Publisher, click the Symantec Corporation link. The Digital Signature Details appears.
    Verify the contents of the following fields to ensure that the tool is authentic:

    Name: Symantec Corporation
    Signing Time: 04/20/2011 3:23:42 PM

    All other operating systems:
    You should see the following message:

    Do you want to install and run "W32.Qakbot Permission Reset Tool" signed on Wednesday, April 20, 2011 3:23:42 PM and distributed by Symantec Corporation?

    The date and time in the digital signature above are based on Pacific time. They will be adjusted your computer's time zone and Regional Options settings.

    If you are using Daylight Saving time, the displayed time will be exactly one hour earlier.

    If this dialog box does not appear, there are two possible reasons:

    The tool is not from Symantec: Unless you are sure that the tool is legitimate and that you downloaded it from the legitimate Symantec Web site, you should not run it.

    The tool is from Symantec and is legitimate: However, your operating system was previously instructed to always trust content from Symantec. For information on this and on how to view the confirmation dialog again, read the document: How to restore the Publisher Authenticity confirmation dialog box.

  8. Click Yes or Run to close the dialog box.
  9. Type exit, and then press Enter. (This will close the MS-DOS session.)