Backdoor.Nibu.G

1. Copies itself as:
   
   
   • %System%\Swchost.exe
   • %System%\Svohost.exe
   • %UserProfile%\Start Menu\Programs\Startup\Svchost.exe
     
     Notes:
   • %System% is a variable. The Trojan locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
   • %UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\[CURRENT USER] (Windows NT/2000/XP).
     
     
2. Creates the following files:
   
   
   • %Windir%\Rundlln.sys
   • %Windir%\Prntsvr.dll
   • %Windir%\Temp\feff35a0.htm
   • %Windir%\Temp\fe43e701.htm
   • %Windir%\Temp\fa4537ef.tmp
     
     Note: %Windir% is a variable. The Trojan locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and creates files in that location.
     
     
3. Adds the value:
   
   "load32" = "%System%\swchost.exe"
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   so that the Trojan runs when Windows starts.
   
   
4. Creates and loads a .dll file to log keystrokes. It has been reported that this file is %Windir%\Prntsvr.dll. The Trojan may hide this process and may recreate it if it is deleted.
   
   
5. May create the registry subkeys:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\SARS
   HKEY_USERS\.DEFAULT\SOFTWARE\SARS
   
   
6. Modifies the value:
   
   "Shell" = "explorer.exe %System%\svohost.exe"
   
   in the registry subkey:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
   
   so that the worm runs when you start Windows NT/2000/XP.
   
   
7. Modifies the %Windir%\System.ini file by adding the value:
   
   "Shell" = "explorer.exe %System%\svohost.exe"
   
   so that the worm runs when you start Windows 95/98/Me.
   
   
8. Logs keystrokes entered into windows that have the following string in the title bar:
   
   [http://]www.whatpornsite.com/[REMOVED]/css/logger.php
   
   
9. Logs windows titles and keystrokes entered into them to the file %Windir%\Prntk.log.
   
   
10. Steals the following information:
    
    
    • IP address of the compromised computer
    • System information
    • Operating system
    • Internet Explorer version
    • FAR Manager passwords
    • FTP Commander passwords
    • Protected storage data
      
      
11. Logs data saved to the clipboard to %Windir%\Prntc.log.
    
    
12. Periodically checks the size of the files used to log the stolen information. When the files reach a certain size, the Trojan sends the stolen information to a remote attacker via email, using its own SMTP engine. The email has the following characteristics:
    
    From: [registered owner] [address@yandex.ru]
    To: you
    
    
13. Creates the following .html file containing the stolen data:
    
    %Windir%\TEMP\feff35a0.htm.
    
    
14. Creates the following raw MIME message containing the stolen data:
    
    %Windir%\TEMP\fa4537ef.tmp
    
    
15. Listens on TCP ports 1001 and 10000 for remote instructions.
    
    
16. Disables access to certain security-related Web sites by adding the following lines to the hosts file:
    
    127.0.0.1  avp.com
    127.0.0.1  ca.com                            
    127.0.0.1  customer.symantec.com            
    127.0.0.1  dispatch.mcafee.com              
    127.0.0.1  download.mcafee.com              
    127.0.0.1  f-secure.com                      
    127.0.0.1  kaspersky.com                    
    127.0.0.1  liveupdate.symantec.com          
    127.0.0.1  liveupdate.symantecliveupdate.com
    127.0.0.1  mast.mcafee.com                  
    127.0.0.1  mcafee.com                        
    127.0.0.1  my-etrust.com                    
    127.0.0.1  nai.com                          
    127.0.0.1  networkassociates.com            
    127.0.0.1  rads.mcafee.com                  
    127.0.0.1  secure.nai.com                    
    127.0.0.1  securityresponse.symantec.com    
    127.0.0.1  sophos.com                        
    127.0.0.1  symantec.com                      
    127.0.0.1  trendmicro.com                    
    127.0.0.1  update.symantec.com              
    127.0.0.1  updates.symantec.com              
    127.0.0.1  us.mcafee.com                    
    127.0.0.1  viruslist.com                    
    127.0.0.1  www.avp.com                      
    127.0.0.1  www.ca.com                        
    127.0.0.1  www.f-secure.com                  
    127.0.0.1  www.kaspersky.com                
    127.0.0.1  www.mcafee.com                    
    127.0.0.1  www.my-etrust.com                
    127.0.0.1  www.nai.com                      
    127.0.0.1  www.networkassociates.com        
    127.0.0.1  www.sophos.com                    
    127.0.0.1  www.symantec.com                  
    127.0.0.1  www.trendmicro.com                
    127.0.0.1  www.viruslist.com

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.