W97M.Trolox.A

SUMMARY

This macro virus infects the Normal.dot template, and uses that template to spread. It has a module named "Wrath" that contains the viral code. Its payload deletes files if the date is July 4 through July 8.

Protection

• Virus Definitions (Intelligent Updater) May 23, 2001

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload Trigger: July 4th to July 8th
• Deletes Files: C:/My Documents/*.* C:/Windows/*.*

Distribution

• Distribution Level: Low
• Target of Infection: Normal.dot and MS-Word documents

TECHNICAL DETAILS

When executed, W97M.Trolox.A does the following:

1. It creates the C:Mswin.dll and C:Mswin2.dll files, which contain the viral module.
2. It then uses those files to export and then import the viral module into the active document or the Normal.dot template.
3. After infecting the document or template, the virus deletes both files.
4. If you are running Microsoft Word 2000, it lowers the Microsoft Word security level to 1.
5. If date is July 4 through July 8, the virus deletes:
   • Files in:
     • C:My Documents
     • C:Windows
   • The C:My Documents folder and displays the message Happy July 4th!!
6. On July 3 the virus changes the Microsoft Word background color to blue. It then executes Notepad and displays the message FEEL MY WRATH.......

Recommendations

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.

REMOVAL

To remove this virus, repair files detected as W97M.Trolox.A, delete the files that it dropped if they still exist, and reset the Word security level if necessary.

NOTE: If the virus has activated on July 4 through July 8, you most likely will first have to reinstall Windows and then restore the contents of the My Documents folder from backup.

To remove the virus:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
3. If any files are detected as infected by W97M.Trolox.A, click Repair.
4. Using Windows Explorer, locate the C:Mswin.dll and C:Mswin2.dll files, and if they are found, delete them.

To reset the Word 2000 security level:

1. Start Microsoft Word.
2. Click Tools, click Macro, and then click Security.
3. Set the security level to Medium or High, and then click OK.