Threat Explorer

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VCL.Pearl Harbour.959

VCL.Pearl Harbour.959

08 October 2001
13 February 2007

VCL.Pearl Harbour.959 is an encrypted variant of the DOS virus VCL.Pearl Harbour. The name of the virus is based on its payload. This virus searches for executable files. When it finds an executable file, it creates a copy of itself with the same file name, but with the .com extension.

VCL.Pearl Harbour.959 is a DOS companion virus. It searches for executables in the root of the drive from which it is executed, and in all subfolders that are contained in the root. When an executable file is found, the virus creates a copy of itself with the same name as the executable file, but with the .com extension.

For example, if the file Timechk.exe is found, the virus will create a copy of itself as Once this occurs, if you type Timechk at a command prompt, will be executed.

The virus has a payload that is executed on December 7th of any year. The payload displays the following message, for which the virus received its name:

December 7th, 1941 -- A day that will live in infamy...


This virus contains a few antidebugging tricks. One of them disables the keyboard. The virus does not re-enable the keyboard after disabling it. Therefore, once the virus has been executed, the keyboard will not work until the computer is restarted.


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.

Run LiveUpdate to make sure that you have the most recent virus definitions.
  1. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
  2. Run a full system scan.
  3. Delete all files that are detected as VCL.Pearl Harbour.959.

Writeup By: Neal Hindocha