W32.HLLC.Happylow

SUMMARY

W32.HLLC.Happylow is a companion virus that encrypts all .exe files that reside in the same folder as the virus and renames them with a .wal extension. It then makes a copy of itself as the original file name.

For example, the virus encrypts the file Calc.exe and renames it to Calc.wal. Then the virus copies itself as Calc.exe, so that when the infected Calc.exe is executed, the virus executes its routine. Finally, it decrypts the Calc.wal file and executes it to make it appear that Calc.exe has run normally.

Protection

• Virus Definitions (LiveUpdate™ Weekly) September 10, 2002
• Virus Definitions (Intelligent Updater) September 10, 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
• Payload Trigger: User types any of the following words: sex, help, porn, shine, walrus, finished, help
• Payload: Displays a graphic of flowers on the screen

Distribution

• Distribution Level: Low
• Target of Infection: .exe files in current folder

TECHNICAL DETAILS

When W32.HLLC.Happylow runs, it copies itself as %windir%Shine.exe.

NOTE: %windir% is a variable. The virus locates the Windows installation folder (by default this is C:Windows or C:Winnt) and copies itself to that location.

The virus adds the value

Shine    %windir%shine.exe /Trigger

to the registry key

HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun

so that the virus runs each time that you start Windows.

Next, it encrypts all .exe files that reside in the same folder as the virus and renames them with a .wal extension. It then makes a copy of itself as the original file name. The virus also uses the same method to infect %windir% otepad.exe.

This method of infection is called companion. The virus simply renames the original file to a different extension and copies itself as the same name of the original file. For example, the virus encrypts Calc.exe and renames it to Calc.wal. Then the virus copies itself as Calc.exe, so that when the infected Calc.exe is executed, the virus execute its routine. Finally, it decrypts the Calc.wal file and executes it to make it appear as if Calc.exe has run normally.

The virus has a harmless payload. If the virus is executed with the /Trigger option or if the infected system is booted and the virus is running, the virus checks whether the following words are typed:

• sex
• help
• porn
• shine
• walrus
• finished
• help

If you type any of these words, then the virus payload is triggered. The payload displays a graphic of colorful happy flowers on the screen.

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

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions
2. Run a full system scan, and delete all files that are detected as W32.HLLC.Happylow. Also delete the .wal files. Replace deleted files with clean backup copies, or reinstall them.
3. Delete the value
   
   Shine    %windir%shine.exe /Trigger
   
   from the registry key
   
   HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun

For details on how to do this, read the following instructions.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:

• Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
• Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
  
  Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

To scan for and delete the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
2. Run a full system scan.
3. If any files are detected as infected with W32.HLLC.Happylow, click Delete.
4. Using Windows Explorer, delete the .wal files that are in the same folder as the virus. Replace deleted files with clean backup copies, or reinstall them.

To delete the value that the virus added to the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the key
   
   HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the value
   
   Shine    %windir%shine.exe /Trigger
   
5. Exit the Registry Editor.