W97M.Marker.O

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Discovered: June 03, 1999
Updated: February 13, 2007 11:59:38 AM
Type: Macro


This is a class-module macro virus that infects Microsoft Word documents and templates. This virus contains a date-activated payload which may insert text and display messages. The Word title bar may also change with references to the word "Shankar."

Antivirus Protection Dates

  • Initial Rapid Release version July 17, 1999
  • Latest Rapid Release version July 17, 1999
  • Initial Daily Certified version July 17, 1999
  • Latest Daily Certified version July 17, 1999

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Patrick Nolan

Discovered: June 03, 1999
Updated: February 13, 2007 11:59:38 AM
Type: Macro


This virus hooks the Word event handler to close documents in order to run its code.

If the month is July and the day of the month is 23 or later, this virus modifies Word title bar with this text:



The full text is "Happy Birthday Shankar-25th July.The World may Forget but not me."

This virus also displays the following dialog box:



If you click Yes, this message is displayed:



Otherwise, this message is displayed:



This virus infects other documents and templates when you open an infected document. It makes the following modifications to the infected documents:

Title: Are You suprised ?
Subject: Birthday
Author: LSK
Category : You Are Infected
Keywords: Birthday
Comments: Shankar's Birthday falls on 25th July. Don't Forget to wish him

If new documents are created in July on the 23rd day or later, this virus inserts the following text into them:



The font size is 72 point.

When you close infected documents, the virus displays a final dialog box:



However, whatever you click, no further action occurs.

Recommendations

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.

Writeup By: Patrick Nolan

Discovered: June 03, 1999
Updated: February 13, 2007 11:59:38 AM
Type: Macro


Run LiveUpdate to make sure that you have the most recent virus definitions.

  1. Start Norton AntiVirus (NAV), and run a full system scan. Be sure that NAV is configured to scan all files.
  2. If any files are detected as infected by W97M.Marker.O, click Repair.
  3. The document properties of each infected document must be modified from within Microsoft Word.


Writeup By: Patrick Nolan