Bat.Hexvirus.1414

SUMMARY

Bat.Hexvirus.1414 is a relatively harmless batch file virus. It attempts to drop two files; the first file turns the second file into an executable file that carries the possibly destructive payload. Due to bugs in the code, the virus does not succeed in infecting the computer, but it does cause the computer to stop responding.

Protection

• Virus Definitions (LiveUpdate™ Weekly) July 13, 2001
• Virus Definitions (Intelligent Updater) July 13, 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

The virus tries to drop a decrypter for the virus into the second file. This decryption program has bugs in it and when the program is run, it crashes the system. The second file is left in a partially decrypted, harmless state. The virus will not run a second time after crashing once. This is because it checks for the existence of the dropped files, and one or both will exist.

NOTE: The files dropped by the virus are -b ,-h.bat, and -1.com. Although the virus is designed to delete these files as part of the routine, the files may not be deleted due to bugs in the code.

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. Note the location of any files detected as Bat.Hexvirus.1414, and then delete them.
4. Using Windows Explorer, go to the folder where the files that were detected as Bat.Hexvirus.1414 were stored.
5. In that folder, look for any files whose file name begin with a dash ( "-"), such as -b ,-h.bat, and -1.com. Delete any such files that you find.
   
   CAUTION: Make sure that these are not data files that you need. If you are not sure, back up the files before you delete them.