W32.HLLC.Pers

SUMMARY

W32.HLLC.Pers is a simple companion virus. It searches for .exe files that are in the same folder as the virus, renames them with the .Lsx extension, and then copies itself as the original .exe file names.

Protection

• Virus Definitions (Intelligent Updater) May 2, 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

When W32.HLLC.Pers is executed, it searches for .exe files in the current directory. If the file name does not begin with Expl, Prog, Emm3, Rund, or Net, then it is renamed with the .Lsx extension, and the attribute is set to hidden. The virus then copies itself as the original file name. If at least one file is infected on the 10th of any month, the payload will activate. The payload drops and executes the Pay.com file, which produces a buzzing sound from your speakers while printing the following text:



After some time, or if a key is pressed, the payload file (Pay.com) terminates, and the host (one of the files that W32.HLLC.Pers first renamed and then copied itself as the original file name) will not be executed.

NOTE: If for any reason the payload is not executed, then the host is copied to a file named Persiana.exe, which is then executed.

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

To remove this worm:

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. Delete any files detected as W32.HLLC.Pers.
4. If W32.HLLC.Pers has run on your system, follow these steps:
   1. Make sure that Windows is set to show all files.
   2. Use Windows Find or Search function to locate all files with the .Lsx extension.
   3. Remove the hidden attribute.
   4. Rename the files back to the .exe extension.