W97M.Gullible

W97M.Gullible is a macro virus that is triggered when you open, close, or create a new document or template in Microsoft Word.

If your Application user name is S. Bach, the virus will not infect your documents or templates.

Type:	Macro
Infection Length:	Variable

Virus Definitions (Intelligent Updater) October 10, 2000

Wild Number of infections: 0 - 49 Number of sites: 0 - 2 Geographical distribution: Low Threat containment: Easy Removal: Easy

Threat Metrics Wild: Low Damage: Low Distribution: Low

Damage

• Payload:
  • Modifies files: Normal.dot

Distribution

• Target of infection: Microsoft Word templates and documents

W97M.Gullible is triggered when you open, close, or create a new document or template in Microsoft Word.

If your Application user name is S. Bach, the virus will not infect your documents or templates.

When a document is closed on March 19th of any year, the Microsoft Office Assistant appears and displays the following message:

Normal.dot was infected by MFV(My First Virus).

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. 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.

Repair infected files with Norton AntiVirus.

Write-up by: Gor Nazaryan