W32.Bagz@mm

SUMMARY

W32.Bagz@mm is a mass-mailing worm that uses its own SMTP engine to send itself to the email addresses gathered from an infected computer.

Protection

• Virus Definitions (LiveUpdate™ Weekly) October 6, 2004
• Virus Definitions (Intelligent Updater) October 4, 2004

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 a mass-mailing.
• Compromises Security Settings: Disables firewalls.

Distribution

• Distribution Level: High
• Subject of Email: Various
• Name of Attachment: Various

TECHNICAL DETAILS

When W32.Bagz@mm is executed, it does the following:

1. Creates the following copy of itself:
   
   %System% utorial.doc <spaces> .exe
   
   Note: %System% is a variable that refers to the System folder. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).
   
   
2. Adds the value:
   
   "syslogin.exe" = "syslogin.exe"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
   so that the worm is executed every time Windows starts.
   
   
3. Creates the following files:
   
   • %System%dl.exe
   • %System%syslogin.exe
     
     
4. Disables the Windows firewall.
   
   
5. Downloads and executes remote files.
   
   
6. Installs its own network driver to bypass local firewalls.
   
   
7. Gathers the email addresses from the files with the following extensions:
   
   • .txt
   • .htm
   • .dbx
   • .tbi
   • .tbb
     
     
8. Stores the email addresses it gathers and the IP address of the local computer and the email gateway in the following temp files:
   
   • %System%jobdb.dll
   • %System%ipdb.dll
   • %System%wdate.dll
     
     
9. Sends itself to the email addresses that it finds. The email has the following characteristics:
   
   From: (spoofed)
   
   Subject: (one of the following)
   
   • Re: User ID Update
   • Fwd: Your Funds are Eligible for Withdrawal
   • find a solution with this customer
   • No Subject
   • Re: Help Desk Registration
   • failure notice
   • Fwd: Password
   • when should i call you?
   • RE: Re: A question
   • Knowledge Base Article
   • Open Invoices
   • Returned mail: see transcript for details
   • building maintenance
   • [Fwd: Broken link]
   • WinXP
   • troubles are back again
   • Questions
   • Order Approval
   • units available
   • progress news
   • big announcements
   • Need help pls
   • You have recieved an eCard!
   • What is this ????
   • Deactivation Notice
   • Message recieved, please confirm
   • My funny stories
   • Cost Inquiry
   • Re: payment
   • referrences
   • Webmail Invite
   • RE: quote request
     
     
     Attachment: (one of the following)
     
   • Ctutorial.doc <spaces> .exe
   • doc.doc <spaces> .exe
   • documents.doc <spaces> .exe
   • atach.doc <spaces> .exe
   • file.doc <spaces> .exe
   • read.doc <spaces> .exe
   • readme.doc <spaces> .exe
   • contact.doc <spaces> .exe
   • mail.doc <spaces> .exe
   • att.doc <spaces> .exe
   • warning.doc <spaces> .exe
   • db.doc <spaces> .exe
   • msg.doc <spaces> .exe
   • message.doc <spaces> .exe
   • messages.doc <spaces> .exe
   • archive.doc <spaces> .exe
   • arch.doc <spaces> .exe
   • support.doc <spaces> .exe
   • account.doc <spaces> .exe
   • doc.zip
   • documents.zip
   • atach.zip
   • file.zip
   • read.zip
   • readme.zip
   • contact.zip
   • mail.zip
   • att.zip
   • warning.zip
   • db.zip
   • msg.zip
   • message.zip
   • messages.zip
   • archive.zip
   • arch.zip
   • support.zip
   • account.zip
     
     
     Message: (one of the following)
     
   • Hello,
     Sorry, I forgot to attach the new contact information.
     Please view the attached (.pdf) contact sheet.
     Sincerely,
     User
     
   • Hello,
     I resent this email as attachment because
     it was previously blocked by your email filters.
     Please read the attachment and respond.
     Thanks,
     User
     
   • Hello,
     I was in a hurry and I forgot to attach an important
     document. Please see attached.
     Best Regards,
     User
     
   • Hello,
     Your email was received.
     YOUR REPLY IS URGENT!
     Please view the attached text file for instructions.
     Regards,
     User
     
   • Hello,
     Your email was sent in an INVALID format.
     To verify this email was sent from you,
     simply open the attached email (.eml) file
     and click yes in the sender options box.
     Thank You,
     User
     
   • Hello,
     My PC crashed while I was sending that last email.
     I have re-attached the document of yours that I discovered.
     Please read attached document and respond ASAP.
     Sincerely,
     User
     
   • Hello,
     What version of windows you are using?
     This last document I received from you came out weird.
     Please see the attached word file and resend the file to me.
     Many thanks,
     User
     
   • ***YOUR MESSAGE HAS BEEN RECOGNIZED AS SPAM***
     Hello,
     The previous email you sent has been recognized as spam.
     This means your email was not delivered to your friend or client.
     You must open the attached file to receive more information.
     ***YOUR MESSAGE HAS BEEN RECOGNIZED AS SPAM***
     
   • ***ATTENTION: YOUR EMAIL IS NOT BEING DELIVERED!***
     You are currently unable to send emails.
     This may be a billing issue.
     Please call the billing center.
     The # for the billing office is located in the attached
     contact list for your convenience.
     ***ATTENTION: YOUR EMAIL IS NOT BEING DELIVERED!***
     
   • ***URGENT: SERVICE SHUTDOWN NOTICE***
     Due to your failure to comply with our email
     Rules and Regulations, your email account has been
     temporarily suspended for 24 hours unless we are contacted regarding
     this situation.
     You must read the attached document for further
     instructions. Failure to comply will result in termination of your account.
     Regards,
     Net Operator
     ***URGENT: SERVICE SHUTDOWN NOTICE***
     
   • last request before refunding

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

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

Important: On computers running Norton AntiVirus 2005 or later, the QuickScan tool will automatically search for and remove malicious threats when new virus definitions are downloaded. While every effort has been made to ensure that the QuickScan tool removes all the traces of a malicious threat from an infected computer, we advise that you confirm that all the files and registry entries have been removed. We recommend following the manual removal steps and deleting any threat-related files or registry entries remaining on the computer.

1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Restart the computer in Safe mode or VGA mode.
4. Run a full system scan and delete all the files detected as W32.Bagz@mm.
5. Delete the value that was added to the registry.
   

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

1. To disable 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"

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.


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. To update 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 daily. 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. To restart the computer in Safe mode or VGA mode

Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.

• For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
• For Windows NT 4 users, restart the computer in VGA mode.

4. To scan for and delete 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.Bagz@mm, click Delete.
   
   
   Note: If your Symantec antivirus product reports that it cannot delete an infected file, Windows may be using the file. To fix this, run the scan in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode." Once you have restarted in Safe mode, run the scan again.
   
   (After the files are deleted, you can leave the computer in Safe mode and proceed with section 4. When that is done, restart the computer in Normal mode.)
   

5 To delete the value from the registry


Important: 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.

1. Click Start > Run.
2. Type regedit
   
   Then click OK.
   
   
3. Navigate to the key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the value:
   
   "syslogin.exe" = "syslogin.exe"
   
   
5. Exit the Registry Editor.