W32.Elkern.dam

SUMMARY

W32.Elkern.dam is a corrupted version of W32.Elkern.4926. Due to the method of infection, W32.Elkern.4926 can corrupt files beyond repair.

Protection

• Virus Definitions (LiveUpdate™ Weekly) July 24, 2002
• Virus Definitions (Intelligent Updater) July 23, 2002

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

A file is detected as W32.Elkern.dam when the file has been corrupted by W32.Elkern.4926.

These files are corrupted in such a way that they cannot be repaired. Typically, the virus inserts the viral code somewhere within the file, overwriting areas of the original file. However, the virus never gains control, so the malicious code is not executed. In many cases, the original file crashes when you attempt to run it. Due to this type of corruption, the file must be restored from backup.

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

Delete files that are detected as W32.Elkern.dam. Restore the original files from backup copies or reinstall them.