W32.Antinny.AX

1. Copies itself as the following:
   
   %System%\Microsoft\svchost.exe
   
   Note: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
   
   
2. Adds the value:
   
   "Windows Security Manager" = "%System%\Microsoft\svchost.exe -c -ax"
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
   
   so that it is executed when Windows starts.
   
   
3. Modifies the value:
   
   "DisableSR" = "1"
   
   in the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore
   
   to disable System Restore.
   
   
4. Creates the following clean file:
   
   %Windir%\svdat.m1v
   
   Note: %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.
   
   
5. Creates the following hidden folders:
   
   
   • %Temp%\4407A9BE6535\6A8C9B51993A
   • %Temp%\4407A9BE6535\773232357FF9
     
     Note: %Temp% is a variable that refers to the Windows temporary folder. By default, this is C:\Windows\TEMP (Windows 95/98/Me/XP) or C:\WINNT\Temp (Windows NT/2000).
     
     
6. Searches the Winny file-sharing network program folder and modifies the file UpFolder.txt.
   
   
7. Adds the folder %Temp%\4407A9BE6535\773232357FF9 as a shared folder in the Winny file-sharing network.
   
   
8. Captures screen shots and saves them as the following file:
   
   %Temp%\4407A9BE6535\773232357FF9\[JAPANESE TEXT][USER NAME][JAPANESE TEXT]([DATE]).jpg
   
   
9. Searches for files with the following extensions:
   
   
   • .doc
   • .xls
   • .eml
   • .ppt
   • .dbx
   • .txt
   • .pdf
     
     
10. Searches for the following files in the Winny file-sharing program folder:
    
    
    • Download.txt
    • kakikomi.txt
    • tab1.txt
    • tab2.txt
      
      
11. Searches for files in the following folders:
    
    
    • %UserProfile%\Favorites
    • %UserProfile%\Recent
    • %UserProfile%\Local Settings\Application Data\[RANDOM]\Identities\[RANDOM]\Microsoft\Outlook Express
      
      
12. Creates .zip files containing the found files and saves them as:
    
    %Temp%\4407A9BE6535\773232357FF9\[JAPANESE TEXT][USER NAME][JAPANESE TEXT].zip
    
    
13. Creates a .zip file that contains a copy of itself with randomly chosen Japanese words taken from the worm body. The worm then copies the .zip file to %Temp%\4407A9BE6535\773232357FF9.
    
    
14. Attempts to end the following processes:
    
    
    • Windows Task Manager (Japanese version)
    • ProcessWalker
    • Process Explorer
      
      
15. Drops and executes the following file, which is a variant of Trojan.Sientok:
    
    %Temp%\sttemp.exe
    
    
16. Drops the following files:
    
    
    • %System%\winsm.exe
    • %System%\ms[RANDOM].exe
      
      
17. Creates the following service:
    
    WindowsSecurityManager
    
    
18. Creates the following registry subkeys:
    
    HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\"WindowsSecurityManager"
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\"WindowsSecurityManager"
    
    
19. Checks current date periodically. The worm may, if the day is Monday and the date is between the 1st and 6th of the month, perform a denial of service attack against the following Web sites:
    
    
    • [http://]www.accsjp/[REMOVED]/.or.jp
    • [http://]www2.accsjp/[REMOVED]/.or.jp

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.