W97M.Titch.H

SUMMARY

W97M.Titch.H is a very simple macro virus. The virus replicates between the global template (Normal.dot) and Microsoft Word documents as the documents are closed. The replication is carried out by exporting the macro module as a file and then importing it into documents and templates.

Protection

• Virus Definitions (Intelligent Updater) February 7, 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

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

W97M.Titch.H is a virus that replicates under Microsoft Word. The macro module is executed as documents are closed inside Microsoft Word. At the top of the viral macro module are the comments:

An experiment in Macro programming ;)
Minimum stealth, no encryption, No payload, No mail replication
If you had looked you could have found and deleted it but..
You probably never knew it was here!
SAD CODE MODIFIED DEC 2000 FOR TRACKING IN HETHEL

In an attempt to hide its malicious actions, this virus disables Microsoft Word macro virus protection. The virus then attempts to check whether it has already infected a document or the Normal.dot template. However, due to a bug in the virus, the check does not work as intended. This macro virus adds itself to the Normal.dot template and to documents every time that it is executed.

The replication is carried out by first exporting the viral macro module as C:Upc116stag.tmp, and then importing it into other documents and templates. This method of replicating is used by several macro viruses.

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

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.Titch.H, click Repair.