W32.Duksten.E@mm

SUMMARY

The W32.Duksten.E@mm worm is a variant of the W32.Duksten@mm worm. It is a mass-mailing worm that uses its own SMTP engine to mail itself to all contacts in the Microsoft Windows Address Book.

The email message has the following characteristics:

From: "Greenpace"<boletin@greenpace.org>
Subject: Nuevas grietas del PrestiGe nos amenazan!
Message Body: (There is no message.)
Attachment: Grietas.zip

Protection

• Virus Definitions (LiveUpdate™ Weekly) December 24, 2002
• Virus Definitions (Intelligent Updater) December 24, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low
• Large Scale E-mailing: Sends itself to all contacts in the Outlook Address Book

Distribution

• Distribution Level: High
• Subject of Email: Nuevas grietas del PrestiGe nos amenazan!
• Name of Attachment: Grietas.zip
• Size of Attachment: 9,848 bytes

TECHNICAL DETAILS

When W32.Duksten.E@mm runs, it does the following:

• Displays this message:

• Copies itself as %system%PresTiGe.exe.

NOTE: %system% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).

• Renames the Windows Registry Editor file %windir%Regedit.exe to %windir%m_Regedit.exe, and then copies itself as %windir%Regedit.exe.

NOTE: %windir% is a variable. The worm locates the Windows installation folder and copies itself to that location. By default, this is C:Windows (Windows 95/98/Me/XP), C:Winnt (Windows NT/2000).

• Creates the following files:
  • %system%P_Base64.xrf, which is a text file that contains the email addresses that the worm finds in the Windows Address Book file.
  • %system%P_Prgrm.zip, which is a zip file that contains the file PresTiGe.exe. The PresTiGe.exe file is a copy of the worm.
  • %system%P_WAB.XRF, which is the MIME encoded file P_Prgrm.zip.

• Adds the value

XRF C:\%System%PresTiGe.exe

to the registry key

HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

so that the worm runs when you start Windows.

The worm searches the registry for the locations of the default mail account and SMTP server. It uses this information to send a zipped copy of itself to all the contacts in the Windows Address Book. The email message has the following characteristics:

From: "Greenpace"<boletin@greenpace.org>
Subject: Nuevas grietas del PrestiGe nos amenazan!
Attachment: Grietas.zip

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

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. Restart the computer in Safe mode.
3. Run a full system scan and delete all the files detected as W32.Duksten.E@mm. Manually delete %system%P_Base64.xrf and %system%P_WAB.XRF.
4. Rename m_Regedit.exe back to Regedit.exe.
5. Remove the value
   
   XRF %System%PresTiGe.exe
   
   from the registry key
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

For further details, read the following instructions.

Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

• Running LiveUpdate, which is the easiest way to obtain the virus definitions. These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate) line at the top of this writeup.
• Downloading the definitions using the Intelligent Updater. The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater) line at the top of this writeup.
  
  The 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.

Restarting the computer in Safe mode
All Windows 32-bit operating systems, except Windows NT, can be restarted in Safe mode. For instructions, read the document How to start the computer in Safe Mode.

Scanning for and deleting the infected files

1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
   • For Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • For Symantec AntiVirus Enterprise products: Read the document How to verify that 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.Duksten.E@mm, click Delete.
4. Using Windows Explorer, delete the files %system%P_Base64.xrf and %system%P_WAB.XRF.

Renaming m-Regedit.exe to Regedit.exe
Follow the instructions for your operating system.

Windows 95/98/Me/NT/2000
1. Click Start, point to Find or Search, and then click Files or Folders.
2. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
3. In the "Named" or "Search for..." box, type, or copy and paste, the file name m_Regedit.exe.
4. Click Find Now or Search Now.
5. Right-click the file that is found, and then click Rename. Change the name to Regedit.exe.

Windows XP
1. Click Start, and then click Search.
2. Click All files and folders.
3. In the "All or part of the file name" box, type, or copy and paste, the file name m_Regedit.exe.
4. Verify that "Look in" is set to "Local Hard Drives" or to (C:).
5. Click "More advanced options."
6. Check "Search system folders."
7. Check "Search subfolders"
8. Click Search.
9. Right-click the file that is found, and then click Rename. Change the name to Regedit.exe.

Removing 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 the specified keys only. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and then click Run. (The Run dialog box appears.)
2. Type regedit, and then click OK. (The Registry Editor opens.)
3. Navigate to the key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the value
   
   XRF %System%PresTiGe.exe
   
5. Exit the Registry Editor.