VBS.Biscuit.A@mm

SUMMARY

VBS.Biscuit.A@mm is a mass-mailing worm that sends itself as an attachment to the first 50 email addresses in the Microsoft Outlook Address Book.
The email message will have the following characteristics:

Subject: Adsl no problem!!!
Attachments: Adsl_no_problem.pdf<184 spaces>.vbs

The worm attempts to copy itself to both the local host and reachable remote network shares. It will copy itself to the root of the network share as Netlog.vbs.
The worm will also copy the original worm filename to the following folders if it is able to copy netlog.vbs to the root of the share:

• <network share root>WindowsMenu AvvioProgrammiEsecuzione automatica
• <network share root>Windowsstartm~1programsstartup
• <network share root>Windows
• <network share root>Windowsstart menuprogramsstartup
• <network share root>Win95start menuprogramsstartup
  

On the 10th of every month, VBS.Biscuit.A@mm will display a pop-up message.

Protection

• Virus Definitions (LiveUpdate™ Weekly) October 1, 2003
• Virus Definitions (Intelligent Updater) September 26, 2003

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: Medium
• Large Scale E-mailing: Sends itself to the first 50 email addresses in the Microsoft Outlook Address Book.

Distribution

• Distribution Level: Medium
• Subject of Email: Adsl no problem!!!
• Name of Attachment: Adsl_no_problem.pdf<184 spaces>.vbs
• Size of Attachment: 13 kb
• Shared Drives: Attempts to copy itself to remote machines.

TECHNICAL DETAILS

When VBS.Biscuit.A@mm is executed, it performs the following actions:

1. Copies itself as:
   • C:MyPhoto.JPG.VBS
   • C:System.dat.vbs
   • C:Adsl_no_problem.pdf
   • %Windir%D4NG3.vbs
   • %Windir%index.html
     
     

     ---

     Note: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:Windows or C:Winnt) and copies itself to that location.

     ---

     
     
2. Creates the following files:
   • %Windir%WallPaper.html
   • %Windir%BasicUpdate.dll.vbs
   • %Windir%untitled.HTM
   • C: etlog.tmp
   • C:Of.txt
   • Script.ini
     
     
3. Adds the values:
   
   "Data" = "c:System.dat.vbs"
   "WinMine" = "%Windir%D4NG3.vbs"
   "WinSetBrowse" = "%Windir%BasicUpdate.dll.vbs"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that the worm runs when you start Windows.
   
   
4. Adds the values:
   
   "OlkContactRefresh" = "0"
   "OlkFolderRefresh" = "0"
   "FirstRun" = "0"
   "UseOutlook" = "0"
   
   to the registry key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWABWAB4
   
   
5. Adds the values:
   
   "Message Send HTML" = "1"
   "Compose Use Stationery" = "1"
   "Stationery Name" = "%Windir%untitled.HTM"
   "Wide Stationery Name" = "%Windir%untitled.HTM"
   
   to the registry key:
   
   HKEY_CURRENT_USERIdentities" & %DUID% & "SoftwareMicrosoftOutlook Express5.0Mail
   
   

   ---

   Note: %DUID% is a variable. The worm uses the value of the Default User ID in the registry key: HKEY_CURRENT_USERIdentitiesDefault User ID.

   ---

   
   
6. Adds the value:
   
   "wallPaper" = "%WindirwallPaper.html"
   
   to the registry key:
   
   HKEY_CURRENT_USERControl Paneldesktop
   
   so that the desktop displays the following wallpaper:
   
   
   
   
7. Adds the value:
   
   "Start Page" = "http:/ /www.sesso.com"
   
   to the registry key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain
   
   so that the start page of Internet Explorer is set to www.sesson.com.
   
   
8. Adds the values:
   
   "Account Name" = "mail.supereva.it"
   "Connection Type" = "0"
   "Make Available Offline" = "1"
   "IMAP Port" = "143"
   "IMAP Timeout" = "60"
   "IMAP Use LSUB" = "1"
   "IMAP Polling" = "1"
   "IMAP Svr-side Special Folders" = "1"
   "IMAP Sent Items Folder" = "Posta inviata"
   "IMAP Drafts Folder" = "Bozze"
   "IMAP Prompt for Password" = "0"
   "IMAP Dirty" = "0"
   "IMAP Poll All Folders" = "1"
   "HTTPMail Prompt for Password" = "0"
   "HTTPMail Polling" = "1"
   "ShowAdBar" = "1"
   "POP3 Server" = "mail.supereva.it"
   "POP3 User Name" = "mp3free1"
   "POP3 Password2" = "hex:01 02 6d 00 61 00 69 00 6c 00 2e 00 73 00 75 00 70 00 65 00 72 00 65 00 76 00 61 00 2e 00 69 00 74 00 34 00 42 00 44 00 37 00 31 00 46 00 45 00 30 00 00 00"
   "POP3 Use Sicily" = "0"
   "POP3 Port" = "110"
   "POP3 Timeout" = "60"
   "POP3 Skip Account" = "1"
   "POP3 Prompt for Password" = "0"
   "SMTP Server" = "mail.supereva.it"
   "SMTP Port" = "25"
   "SMTP Timeout" = "60"
   "SMTP Display Name" = "ss dd"
   "SMTP Email Address" = "mp3free1@supereva.it"
   "SMTP Split Messages" = "0"
   "SMTP Split Message Size" = "64"
   "=?SMTP Prompt for Password" = "0"
   
   to the registry key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftOfficeOutlookOMI Account ManagerAccounts0000001
   
   so that it creates a mail account mail.supereva.it in Microsoft Outlook. This may cause an existing mail account to be deleted or overwritten if one exists.
   
   
9. On the 10th of every month, displays the following message:
   
   
   
   
   
10. Searches for files that have these extensions:
    • jpg
    • jpeg
    • dwg
    • bak
    • doc
    • html
    • xls
    • mdb
    • txt
    • mp3
    • gif
    • png
    • htm
      
      and sets the attributes to Hidden. The worm also copies itself as the same filename and appends .vbs to the filename.
      
      
11. Pings IP addresses from 192.168.0.0 to 255.255.255.255, and, if the host is reachable, copies itself to:
    • <network share root>WindowsMenu AvvioProgrammiEsecuzione automatica
    • <network share root>Windowsstartm~1programsstartup
    • <network share root>Windows
    • <network share root>Windowsstart menuprogramsstartup
    • <network share root>Win95start menuprogramsstartup
      
      
12. Searches for C:Of.txt and sends email messages to the first 50 entries in the Microsoft Outlook Address Book if it does not exist.
    The email message has the following characteristics:
    
    Subject: Adsl no problem!!!
    Message: <empty>
    Attachments: Adsl_no_problem.pdf <184 spaces>.vbs (13 KB)
    
    

    ---

    Note: VBS.Biscuit.A@mm may not complete its payload due to a bug in its code. In such cases, an error messge will be displayed.

    ---

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.

1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Run a full system scan and delete all the files detected as VBS.Biscuit.A@mm.
4. Delete the values that were added to the registry.
   

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"

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. 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 VBS.Biscuit.A@mm, click Delete.

4. Deleting the value from the registry

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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_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the values:
   
   "Data" = "c:System.dat.vbs"
   "WinMine" = "%Windir%D4NG3.vbs"
   "WinSetBrowse" = "%Windir%BasicUpdate.dll.vbs"
   
   
5. Navigate to the key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWABWAB4
   
   
6. In the right pane, delete the values:
   
   "OlkContactRefresh" = "0"
   "OlkFolderRefresh" = "0"
   "FirstRun" = "0"
   "UseOutlook" = "0"
   
   
7. Navigate to the key:
   
   HKEY_CURRENT_USERIdentities" & %DUID% & "SoftwareMicrosoftOutlook Express5.0Mail
   
   
8. In the right pane, delete the values:
   
   "Message Send HTML" = "1"
   "Compose Use Stationery" = "1"
   "Stationery Name" = "%Windir%untitled.HTM"
   "Wide Stationery Name" = "%Windir%untitled.HTM"
   
   
9. Navigate to the key:
   
   HKEY_CURRENT_USERControl Paneldesktop
   
   
10. In the right pane, delete the value:
    
    "wallPaper" = "%WindirwallPaper.html"
    
    
11. Navigate to the key:
    
    HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain
    
    
12. In the right pane, delete the value:
    
    "Start Page" = "http:/ /www.sesso.com"
    
    
13. Navigate to the key:
    
    HKEY_CURRENT_USERSoftwareMicrosoftOfficeOutlookOMI Account ManagerAccounts
    
    
14. In the left pane, delete the subkey:
    
    "00000001"
    
    
15. Exit the Registry Editor.