W97M.Corner.A

SUMMARY

{W97M,P98M}.Corner.A infects Microsoft Project and Microsoft Word files. It is the first macro virus to infect Microsoft Project 98 files. This macro virus does not have a malicious payload.

Protection

• Virus Definitions (Intelligent Updater) November 5, 1999

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

In Microsoft Word:

The MS Word infection routine is very ordinary (NAV heuristically detects infected MS Word documents). Added to this, however, is a routine that adds a new project to MS Project 98 (if MS Project 98 is currently running). The virus performs the infection routine whenever a document is opened or closed.

As with most macro viruses today, it also

• Disables the Tools-Macro menu
• Turns off MacroVirusProtection
• Sets MS Office 2000 security setting to "Low"

An infected MS Project 98 file infects all currently opened projects when it is deactivated (i.e. editing another project file while the infected file is still open). It also re-infects the global template of Microsoft Word (NORMAL.DOT).

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.