W32.Dinoxi

1. Displays the following message:
   
   
   
   
2. Creates the following files:
   
   
   • C:\Documents and Settings\All users\Start Menu\Programs\Startup\Dioxin.exe
   • %System%\System32\Dioxin.exe
   • %System%\System32\WinDio778.exe
   • A:\Dioxin.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).
     
     
3. Adds the value:
   
   "ScanRegistry" = ""
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   so that the worm runs every time Windows starts.
   
   
4. Adds the value:
   
   "SchedulingAgent" = ""
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
   
   so that the worm runs every time Windows starts.
   
   
5. Adds the values:
   
   "DisableTaskmgr" = "1"
   "DisableRegistryTools" = "1"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
   
   to disable the Windows Task Manager and the Registry Editor.
   
   
6. Adds the value:
   
   "Disabled" = "1"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\WinOldApp
   
   to modify settings on the compromised computer and make it difficult to remove the threat.
   
   
7. Adds the value:
   
   "NoDevMgrPage" = "1"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
   
   to disable the Device Manager page.
   
   
8. Adds the value:
   
   "NoRealMode" = "1"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\WinOldApp
   
   to disable real mode DOS.
   
   
9. Adds the values:
   
   "NoRun" = "hex:01,00,"
   "NoFind" = "1"
   "NoClose" = "hex:01,00,"
   "NoLogOff" = "hex:01,00,"
   "NoDrives" = "3FFFFFF"
   "NoDesktop" = "1"
   "NoSaveSettings" = "hex:00,00,"
   "NoViewContextMenu" = "hex:01,00,"
   "NoTrayContextMenu" = "hex:01,00,"
   "RestrictRun" = "1"
   "NoSetFolders" = "F4240"
   "NoFavoritesMenu" = "1"
   "NoRecentDocsMenu" = "1"
   "NoSetTaskbar" = "1"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
   
   in order to change Windows Explorer settings.
   
   
10. Adds the value:
    
    "NoBrowserClose" = "1"
    
    to the registry subkey:
    
    HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Restrictions
    
    to disable the option of closing Internet Explorer.
    
    
11. Modifies the value:
    
    "Start Page" = "[http:]//www.ud7swe.t35.com/[REMOVED]/3wY26ss.com"
    
    in the registry subkey:
    
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    
    in order to change the Internet Explorer start page.
    
    
12. Modifies the values:
    
    "LegalNoticeCaption" = "??????"
    "LegalNoticeText" = "???????????"
    
    in the registry subkey:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Winlogon
    
    
13. Modifies the value:
    
    "NoDesktop" = "1"
    
    in the registry subkey:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    
    to hide all the items and programs on the Windows desktop.
    
    
14. Modifies the value:
    
    "(Default)" = "C:\Windows\System\Browseui.dll-"
    
    in the registry subkey:
    
    HKEY_CLASSES_ROOT\CLSID\{01E04581-4EEE-11d0-BFE9-00AA005B4383}\InProcServer32
    
    to hide Address Bar from Internet Explorer.
    
    
15. Modifies the value:
    
    "@" = "txtfile"
    
    in the registry subkeys:
    
    HKEY_CLASSES_ROOT\.inf
    HKEY_CLASSES_ROOT\.reg
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.inf
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.reg
    
    
16. Modifies the value:
    
    "@" ="rem [ViewFolder(%l, %I, %S)]"
    
    in the registry subkeys:
    
    HKEY_CLASSES_ROOT\Folder\shell\explore\ddeexec
    HKEY_CLASSES_ROOT\Folder\shell\open\ddeexec
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\explore\ddeexec
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\open\ddeexec
    
    
17. Modifies the values:
    
    "s1159" = "??????"
    "s2359" = "??????"
    "STimeFormat" = "HH:mm:ss tt"
    
    in the registry subkey:
    
    HKEY_CURRENT_USER\Control Panel\International
    
    to change the time format settings.
    
    
18. Modifies the value:
    
    "KeyboardDelay" = "9"
    
    in the registry subkey:
    
    HKEY_CURRENT_USER\Control Panel\Keyboard
    
    to change the display settings.
    
    
19. Modifies the values:
    
    "DoubleClickSpeed" = "100"
    "MouseSensitivity" = "5"
    "MouseSpeed" = "0"
    "SwapMouseButtons" = "1"
    
    in the registry subkey:
    
    HKEY_CURRENT_USER\Control Panel\Mouse
    
    to change the mouse settings.
    
    
20. Sends an instant message to all the AOL Instant Messenger contacts on the compromised computer.
    This message contains one of the following strings:
    
    
    • Aim Hacker 1.3 FREE!
    • Best Aim Password Cracker written by ZeX.
    • Better then limewire and kazaa put together!
    • Check my Pics Out!
    • Check out my music!
    • Check out my webcam.
    • Click to join! Better then myspace and xanga!
    • Cool hacking programs!
    • Download Aim Optimized 4.9!
    • Download Dead Aim (5.9+)- NEW!
    • Download my mp3 i made.
    • Download My Profile.
    • Email Hacker Pro 1.5 This is awsome! :)
    • Free Aim Password Cracker. Use it to hack your friends.
    • Funniest Clip Ever!
    • Game Hacker program download here.
    • Get X-im Chat! Better then AIM!
    • Hack Webcams and Aim accounts with O-Hax! This is the last day it will be out for free!
    • Have you see this!
    • INFINITE FREE PICS OF ASIAN HOTTIES!
    • Join this free music site!
    • LMAO OMG THIS IS HILARIOUS!
    • LOL Check these Pics out.
    • Lol OMG! Someone posted your picture here!
    • LOL Watch this clip!
    • LOLOL WTF IS THIS?!
    • Make your own Profile!
    • My Xanga!
    • OMG LOOK IT'S YOU!
    • Play the new Aim Online game!
    • See my Beach pictures!!
    • Take my Quiz!
    • THE KEY TO HAPPINESS IS LAUGHTER!
    • This game is badass! Play now!
    • View My BuddyProfile
    • Wanna See My Profile!
      
      These messages will contain the following link, which will download a copy of W32.Dinoxi.B, if clicked:
      
      [http:]//www.yu9.us/[REMOVED]/o.exe
      
      
21. Opens a back door by connecting to a predetermined location, using a random port, and listening for commands. These commands allow a remote attacker to perform various actions on the compromised computer, including downloading and executing remote files.

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.