WNT.Energy.worm

SUMMARY

WNT.Energy.worm is an email worm. It runs under Windows NT and 2000 only. The worm runs as a service and copies its code into running processes. It hooks the MAPISendMail function and adds itself as Setup.exe to any RAR archives in outgoing mail.

Protection

• Virus Definitions (Intelligent Updater) November 16, 2000

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
• Modifies Files: Copies its code into memory of running processes.
• Compromises Security Settings: Hooks MAPISendMail function in other processes

Distribution

• Distribution Level: Low
• Subject of Email: Uses existing subject lines.
• Name of Attachment: Uses existing attachment name, adds Setup.exe to RAR archives.
• Size of Attachment: 10,752 bytes inside the archive.

TECHNICAL DETAILS

Upon startup, the worm copies itself as Energy.exe into the WindowsSystem directory and loads this file as a service called EnErGy. The worm then periodically enumerates through all running processes, copies itself to them, and runs its code from there.

Eventually, the worm infects nearly every process in the computer. The worm hooks the MAPISendMail function in any process that imports the MAPI32.dll, and adds itself as Setup.exe to any RAR archives in outgoing mail. This action is not restricted to any particular mail client.

The worm gets its name from a text string in its body; however, this string is not visible until the file is decrypted and decompressed.

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

The Energy.exe worm program runs as a Win NT service. Consequently, it must be disabled, then deleted. Restart the computer after deletion.