Digi.3547

SUMMARY

This virus is a simple memory-resident .COM and .EXE file infecting virus that targets the Command.com file and contains a destructive payload.

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: 28th of May

Distribution

• Distribution Level: Low
• Target of Infection: COMMAND.COM

TECHNICAL DETAILS

When the trigger condition is met, the virus overwrites every side of the first 20 cylinders of the hard drive, starting at physical location cylinder 0 side 0 sector 1. It also stores the word DIGI in the sectors.

When the virus activity is complete, the screen is cleared and a blue border and blue line appear, and the following message is displayed:

THIS IS A NEW … DELIVER II S&198;ëâl&198;H ® WRITE BY DiGiT! … SOUTH POLAND 1995

After this message appears, the virus displays a flag on the screen and plays music.

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.