Threat Explorer

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13 February 2007
Risk Impact:
File Names:
aso.exe Help.chm License.rtf RegisterNow.url aso.exe aso.ini data.raw readme.txt uninstall
Systems Affected:


Spyware.ASObserver is an application which captures screenshots at specified intervals. These screenshots are stored on the computer and can be accessed at a later time. The application can be configured to start recording silently on start up.


Your Symantec program detects Spyware.ASObserver.


This program can be manually installed or installed as part of another application.

Antivirus Protection Dates

  • Initial Rapid Release version 02 October 2014 revision 022
  • Latest Rapid Release version 07 May 2019 revision 006
  • Initial Daily Certified version 08 February 2006
  • Latest Daily Certified version 07 May 2019 revision 008
  • Initial Weekly Certified release date 08 February 2006
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When Spyware.ASObserver is executed, it performs the following actions:
  1. Creates the following files:

    • %ProgramFiles%\Mildware\ASO\aso.exe
    • %ProgramFiles%\Mildware\ASO\Help.chm
    • %ProgramFiles%\Mildware\ASO\License.rtf
    • %ProgramFiles%\Mildware\ASO\RegisterNow.url
    • %ProgramFiles%\Mildware\ASO\aso.exe
    • %ProgramFiles%\Mildware\ASO\aso.ini
    • %ProgramFiles%\Mildware\ASO\data.raw
    • %ProgramFiles%\Mildware\ASO\readme.txt
    • %ProgramFiles%\Mildware\ASO\uninstall.exe
    • %UserProfile%\Start Menu\Programs\Mildware\ASO\ASO.lnk
    • %UserProfile%\Start Menu\Programs\ASO\Help.lnk
    • %UserProfile%\Start Menu\Programs\ASO\License.lnk
    • %UserProfile%\Start Menu\Programs\ASO\Register Now.lnk
    • %UserProfile%\Start Menu\Programs\ASO\Uninstall.lnk
    • %Windir%\msvcvbq.dll

    • %ProgramFiles% is a variable that refers to the program files folder. By default, this is C:\Program Files.
    • %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).
    • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.

  2. Creates the following registry subkeys:


  3. Adds the value:

    "ASO" =  "C:\Program Files\Mildware\ASO\aso.exe /s"

    to the registry subkey:


    so that the program starts when Windows starts.

  4. Takes screenshots of the compromised computer's display, allowing all user activity visible onscreen to be recorded. The program can also be configured to capture the entire screen or the top-level window each time. The frequency at which screen captures occur can be configured, allowing a maximum rate of one screenshot per second. The default rate of is one screenshot every 30 seconds.

  5. Stores the screenshots locally so that they can be viewed as a HTML report.

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.
  4. Delete any values added to the registry.
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:
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 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, click Delete.

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:


  5. In the right pane, delete the value:

    "ASO" =  "C:\Program Files\Mildware\ASO\aso.exe /s"

  6. Delete the following registry subkeys:


  7. Exit the Registry Editor.