W32.HLLW.Ultimax

SUMMARY

W32.HLLW.Ultimax is a worm that copies itself into the startup folder on open shares. It also attempts to download and run a file that gives access to pornographic material. Several variants are detected as W32.HLLW.Ultimax.

Behavior

Symptoms

Transmission

Protection

• Virus Definitions (LiveUpdate™ Weekly) July 17, 2002
• Virus Definitions (Intelligent Updater) July 17, 2002

Threat Assessment

Wild

• Wild Level: Medium
• Number of Infections: More than 1000
• Number of Sites: More than 10
• Geographical Distribution: Medium
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low
• Degrades Performance: Network performance will suffer greatly as the worm attempts to spread.

Distribution

• Distribution Level: Medium
• Shared Drives: Copies itself across open shares.

TECHNICAL DETAILS

When W32.HLLW.Ultimax is first executed, it copies itself as C:\%windir%Rdvs.exe, or C:\%System%<original file name>, depending on the variant.

NOTES:

• %windir% is a variable. The worm locates the Windows main installation folder (by default this is C:Windows or C:Winnt) and may copy itself to that location.
• %System% is a variable. The worm locates the Windows System folder (by default this is C:WindowsSystem or C:WinntSystem32) and may copy itself to that location.
• Variations on the file name that it copies itself as have been reported, for example, C:\%windir%Rdve.exe.

It then downloads and runs a file that gives access to a pornographic service.

The worm attempts to connect to random IP addresses, and it searches shares to find the %windir% folder on remote computers.

If the worm finds the %windir% folder, it then uses various language-dependent variations of the %startup% folder to attempt to guess the name of the %startup% folder and copy itself to that location.

If it is successful, then when the computer is restarted, the worm creates one of the following values (depending on the variant):

fn

or,

rdvs C:\%System%<the worm file name>

in the registry key

HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun

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, and run a full system scan. Delete all files that are detected as W32.HLLW.Ultimax.
2. Delete the value
   
   fn
   
   or,
   
   rdvs C:\%System%<the worm file name>
   
   from the registry key
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun

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

To scan for and delete the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and 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 have undergone full quality assurance testing by Symantec Security Response. They 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.
     
2. Start your Symantec antivirus program, and ensure 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.
3. Run a full system scan.
4. If any files are detected as infected by W32.HLLW.Ultimax, click Delete.
   
   NOTE: If your Symantec antivirus program reports that it cannot delete an infected file, the file may be running in memory. In this case, you must shut down the computer, turn off the power, and wait 30 seconds. Then restart the computer in Safe mode and run the scan again. All Windows 32-bit operating systems, except Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document How to start the computer in Safe Mode.

To remove the value from 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 following key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete any or the following (or very similar) values:
   
   fn
   
   rdvs C:\%System%<the worm file name>
   
5. Exit the Registry Editor.