Trojan.Bookmarker.J

1. Copies itself as the following file:
   
   %Windir%\inet20004\[FILE NAME]
   
   Note:
   • [FILE NAME] may be either services.exe or winlogon.exe.
   • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows (Windows 95/98/Me/XP) or C:\Winnt (Windows NT/2000).
     
     
2. Deletes the following files:
   
   
   • C:\web.exe
   • C:\Documents and Settings\All Users\Start Menu\Startup\Microsoft Office.hta
     
     
3. Adds the value:
   
   "xp_system" = "%Windir%\inet20004\[FILE NAME]"
   
   to the registry subkeys:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
   HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
   
   so that it is executed every time Windows starts.
   
   
4. Adds one of the following lines to the %Windir%\SYSTEM.INI file or %Windir%\WIN.INI file so that it is executed every time Windows starts:
   
   
   • "load=%Windir%\inet20004\[FILE NAME"
   • "run=%Windir%\inet20004\[FILE NAME]"
     
     
5. Creates the following registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{5321E378-FFAD-4999-8C62-03CA8155F0B3}
   
   
6. Adds the value:
   
   "Enable Browser Extensions" = "yes"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
   
   
7. Downloads files from the following Web sites:
   
   
   • [http://]kannylizaciya.info/[REMOVED]
   • [http://]hilarius.info[REMOVED]
   • [http://]gaddybaby.info[REMOVED]
   • [http://]traff-store.com[REMOVED]
     
     
8. Sends confidential system information to the above Web sites.
   
   
9. Downloads copy of Trojan.Spamforo from [http://]kannylizaciya.info/[REMOVED].
   
   
10. Opens a back door, which allows a remote attacker to perform the following actions on the compromised computer:
    
    
    • Download and execute remote files
    • Modify the registry
    • Add Web sites to the Trusted Sites list of Internet Explorer
    • Add Web sites to the Internet Explorer Favorites menu
    • Hijack Internet Explorer sessions to redirect the browser to potentially malicious Web sites
    • Open hidden Internet Explorer windows and navigate to a chosen Web site
    • Install a Browser Helper Object for Internet Explorer
      
      
11. Alters the Internet Explorer home page, search page, and search bar by modifying the following registry subkeys:
    
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Start Page
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Search Page
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Search Bar
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\SearchURL

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
• 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.
• Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
• Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
• Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
• Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
• If a 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate compromised computers quickly to prevent threats from spreading further. 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.
• If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
• For further information on the terms used in this document, please refer to the Security Response glossary.