W32.Beagle.C@mm

SUMMARY

W32.Beagle.C@mm is a mass-mailing worm that opens a backdoor on TCP port 2745. The worm uses its own SMTP engine for email propagation. It can also send to the attacker the port on which the backdoor listens, as well as a randomized ID number.

The email has the following characteristics:

From: <spoofed>
Subject: <variable>
Attachment: <random characters.exe> within a .zip file


Note:
Virus definitions version 60217w (extended version 2/17/2004 rev 23) detect this sample as W32.Beagle.A@mm.

Protection

• Virus Definitions (LiveUpdate™ Weekly) February 27, 2004
• Virus Definitions (Intelligent Updater) February 27, 2004

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 50 - 999
• Number of Sites: More than 10
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Medium
• Large Scale E-mailing: Sends itself to the email addresses found in the files with the following extensions: .wab, .txt, .htm, .html, .dbx, .mdx, .eml, .nch, .mmf, .ods, .cfg, .asp, .php, .pl , .adb, .sht
• Compromises Security Settings: Attempts to terminate processes responsible for providing updates to various antivirus programs.

Distribution

• Distribution Level: High
• Subject of Email: Variable
• Name of Attachment: [Random Characters].exe
• Size of Attachment: 15,994 bytes
• Ports: TCP 2745

TECHNICAL DETAILS

When W32.Beagle.C@mm is executed, it performs the following actions:

1. Checks the computer date, and if it is after March 14, 2004, the worm will exit.
   
   
2. Creates a mutex named "imain_mutex," which allows only one instance of the worm to execute.
   
   
3. If the worm is not executed from %System%eadme.exe, it will launch notepad.exe, which is the Notepad text editor.
   
   

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   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).

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4. Copies itself as %System%eadme.exe.
   
   
5. Creates the following files:
   
   • %System%onde.exe (18,944 bytes): DLL file, mass-mailer module, detected as W32.Beagle.A@mm
   • %System%doc.exe (1,536 bytes): DLL file, the loader of onde.exe
   • %System%eadme.exeopen (15,994 bytes): ZIP file
     
     
6. Injects onde.exe as a DLL into the address space of the explorer.exe process. This DLL performs the mass mailing.
   
   
7. Adds the value:
   
   "gouday.exe"="%System%eadme.exe"
   
   to the registry key:
   
   HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that W32.Beagle.C@mm runs when you start Windows.
   
   
8. Adds the values:
   
   "uid"="[Random Value]"
   "port"="2745"
   "frun"="1"
   
   to the registry key:
   
   HKEY_CURRENT_USERSOFTWAREDateTime2
   
   The attacker uses the random value inserted in the "uid" value as a unique identifier.
   
   
9. Opens a backdoor on TCP port 2745.
   
   If an attacker sends a specially formatted data message to the port, the worm will allow an arbitrary file to be downloaded to the %Windir% folder. This file will be saved as %Windir%iuplda<x>.exe, where <x> is a random string of characters.
   
   
10. Sends HTTP GET requests to the following Web sites on TCP port 80:
    
    • permail.uni-muenster.de
    • www.songtext.net/de
    • www.sportscheck.de
      
      
      The GET request includes the port number on which the infected computer listens, and the ID number saved in the "uid" key in the Windows registry. Also, by connecting to the Web server, the IP address is sent.
      
      
11. Attempts to end the following processes, which appear to be responsible for updating the signatures of the various antivirus programs:
    
    • ATUPDATER.EXE
    • AVWUPD32.EXE  
    • AVPUPD.EXE    
    • LUALL.EXE    
    • DRWEBUPW.EXE  
    • ICSSUPPNT.EXE
    • ICSUPP95.EXE  
    • UPDATE.EXE    
    • NUPGRADE.EXE  
    • ATUPDATER.EXE
    • AUPDATE.EXE  
    • AUTODOWN.EXE  
    • AUTOTRACE.EXE
    • AUTOUPDATE.EXE
    • AVXQUAR.EXE  
    • CFIAUDIT.EXE  
    • MCUPDATE.EXE  
    • NUPGRADE.EXE  
    • OUTPOST.EXE  
    • AVLTMAIN.EXE  
      
      
12. Scans the local drives for the email addresses in the files with the following extensions:
    
    • .wab
    • .txt
    • .htm
    • .html
    • .dbx
    • .mdx
    • .eml
    • .nch
    • .mmf
    • .ods
    • .cfg
    • .asp
    • .php
    • .pl
    • .adb
    • .sht
      
      
13. Uses its own SMTP engine to send itself to the email addresses found in those files. This worm contains its own MIME-encoding routine, and it will compose the email in memory and send it to all the email addresses it finds.
    
    The email has the following characteristics:
    
    From: (spoofed)
    Subject: (One of the following)
    
    • Accounts department
    • Ahtung!
    • Camila
    • Daily activity report
    • Flayers among us
    • Freedom for everyone
    • From Hair-cutter
    • From me
    • Greet the day
    • Hardware devices price-list
    • Hello my friend
    • Hi!
    • Jenny
    • Jessica
    • Looking for the report
    • Maria
    • Melissa
    • Monthly incomings summary
    • New Price-list
    • Price
    • Price list
    • Pricelist
    • Price-list
    • Proclivity to servitude
    • Registration confirmation
    • The account
    • The employee
    • The summary
    • USA government abolishes the capital punishment
    • Weekly activity report
    • Well...
    • You are dismissed
    • You really love me? he he
      
      
14. Body: (Empty)
    Attachment: <random characters>.exe within a .zip file
    
    The worm will not send any email messages to the addresses containing any of the following strings:
    • .ch
    • @hotmail.com
    • @msn.com
    • @microsoft
    • @avp.
    • noreply
    • local
    • root@
    • postmaster@

The .exe will use the following icon in an attempt to deceive users into believing it is a Microsoft Excel worksheet:

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

Removal using the W32.Beagle@mm Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of W32.Beagle.C@mm. Try this tool first, as it is the easiest way to remove this threat.

Manual Removal
As an alternative to using the removal tool, you can manually remove this threat.

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Reverse the changes that the worm made to the registry, and then restart computer.
4. Run a full system scan and delete all the files detected as W32.Beagle.C@mm and W32.Beagle.A@mm.
   

For specific details on each of these steps, read the following instructions.

1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"

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Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.

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For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.


2. 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 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).
• 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).
  
  The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. Reversing the changes that the worm made to the registry and restart the computer

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WARNING: Symantec strongly recommends that you back up the registry before making 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.

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1. Click Start, and then click Run. (The Run dialog box appears.)
2. Type regedit
   
   Then click OK. (The Registry Editor opens.)
   
   
3. Navigate to the key:
   
   HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the value:
   
   "gouday.exe"="%System%eadme.exe"
   
   
5. Navigate to the key:
   
   HKEY_CURRENT_USERSOFTWAREDateTime2
   
   
6. In the right pane, delete the values:
   
   "uid"="[Random Value]"
   "port"="2745"
   "frun"="1"
   
   
7. Exit the Registry Editor.
   
   
8. Restart the computer.

4. 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.Beagle.C@mm and W32.Beagle.A@mm, click Delete.