Threat Description



Aliases:Backdoor:​W32/SubSeven, SubSeven, Backdoor.SubSeven


A remote administration utility that bypasses normal security mechanisms to secretly control a program, computer or network.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.


You may wish to refer to the Support Community for further assistance. You also may also refer to General Removal Instructions for a general guide on alternative disinfection actions.

Technical Details

Backdoor:W32/SubSeven is a backdoor program that allows a remote user to perform a large range of actions on the affected system.

The first samples of this backdoor were not packed, but later some packed versions appeared which were not easy to detect with contemporary anti-virus programs that had no Win32 'Aspack' file compressor unpacking support.

SubSeven backdoor was first discovered in May, 1999. The backdoor is usually distributed under different names via newsgroups and e-mails.


When run, the backdoor copies itself to the Windows directory with the original name of the file it was run from or as SERVER.EXE, KERNEL16.DL, RUNDLL16.COM, SYSTEMTRAYICON!.EXE or WINDOW.EXE (names are different in different versions of SubSeven).

Then it unpacks a single DLL file to the Windows System directory - WATCHING.DLL (some versions don't do this). After that the backdoor patches Windows Registry so that its main application will be run during every Windows bootup (Run or RunServices keys). Finally, it creates and modifies some other Registry keys. The backdoor can also install itself to the system by modifying either the WIN.INI or the SYSTEM.INI file.

The latest versions of the SubSeven backdoor drop a small starter program (usually WINDOS.EXE) and register it to be run when any EXE file is started in Windows. By doing this the backdoor ensures that its copy is always in the memory. For specific instructions of how to disinfect these versions please see the bottom of the page.

All the recent versions of SubSeven are supplied with a server configuration utility that allows it to customize server part capabilities - installation method, custom startup message, etc. This method was first introduced by the Back Orifice 2000 backdoor and it allows much more flexibility to backdoors.


If the SubSeven backdoor task is being active in the memory (and invisible in Task Manager), it looks for TCP/IP connections and if they are established it listens to TCP/IP ports for commands from a client part.

Subseven also tries to use ICQ, IRC and different e-mail accounts to notify the author that his victims are online.

SubSeven's initial version had the following 113 capabilities:

 Fun Manager 
 1. Open Web Browser to specified location. 
 2. Restart Windows. 
 3. Reverse Mouse buttons. 
 4. Hide Mouse Pointer. 
 5. Move Mouse. 
 6. Mouse Trail Config. 
 7. Set Volume. 
 8. Record Sound file from remote mic. 
 9. Change Windows Colors / Restore. 
 10. Hung up Internet Connection.
 11. Change Time. 
 12. Change Date. 
 13. Change Screen resolution. 
 14. Hide Desktop Icons / Show 
 15. Hide Start Button / Show 
 16. Hide taskbar / Show 
 17. Opne CD-ROM Drive / Close 
 18. Beep computer Speaker / Stop 
 19. Turn Monitor Off / On 
 20. Disable CTRL+ALT+DEL / Enable 
 21. Turn on Scroll Lock / Off 
 22. Turn on Caps Locl / Off 
 23. Turn on Num Lock / Off 
 Connection Manager 
 1. Connect / Disconnect 
 2. IP Scanner 
 3. IP Address book 
 4. Get Computer Name 
 5. Get User Name 
 6. Get Windows and System Folder Names 
 7. Get Computer Company 
 8. Get Windows Version 
 9. Get Windows Platform 
 10. Get Current Resolution 
 11. Get DirectX Version 
 12. Get Current Bytes per Pixel settings 
 13. Get CPU Vendor 
 14. Get CPU Speed 
 15. Get Hard Drive Size 
 16. Get Hard Drive Free Space 
 17. Change Server Port 
 18. Set Server Password 
 19. Update Server 
 20. Close Server 
 21. Remove Server 
 22. ICQ Pager Connection Notify 
 23. IRC Connection Notify 
 24. E-Mail Connection Notify 
 Keyboard Manager 
 1. Enable Key Logger / Disable 
 2. Open Key Logger in a remote Window 
 3. Clear the Key Logger Windows 
 4. Collect Keys pressed while Offline 
 5. Open Chat Victim + Controller 
 6. Open Chat among all connected 
 1. Windows Pop-up Message Manager 
 2. Disable Keyboard 
 3. Send Keys to a remote Window 
 Misc. Manager 
 1. Full Screen Capture 
 2. Continues Thumbnail Capture 
 3. Flip Screen 
 4. Open FTP Server 
 5. Find Files 
 6. Capture from Computer Camera 
 7. List Recorded Passwords 
 8. List Cached Passwords 
 9. Clear Password List 
 10. Registry Editor 
 11. Send Text ot Printer 
 File Manager 
 1. Show files/folders and navigate 
 2. List Drives 
 3. Execute Application 
 4. Enter Manual Command 
 5. Type path Manually 
 6. Download files 
 7. Upload files 
 8. Get File Size 
 9. Delete File 
 10. Play *.WAV 
 11. Set Wallpaper 
 12. Print *.TXT\*.RTF file 
 13. Show Image 
 Window Manager 
 1. List visible windows 
 2. List All Active Applications 
 3. Focus on Window 
 4. Close Window 
 5. Disable X (close) button 
 6. Hide a Window from view. 
 7. Show a Hidden Window 
 8. Disable Window 
 9. Enable Disabled Window 
 Options Menu 
 1. Set Quality of Full Screen Capture 
 2. Set Quality of Thumbnail Capture 
 3. Set Chat font size and Colors 
 4. Set Client's User Name 
 5. Set local 'Download' Directory 
 6. Set Quick Help 
 7. Set Client Skin 
 8. Set Fun Manager Skin 
 Edit Server 
 1. PreSet Target Port 
 2. PreSet server Password 
 3. Attach EXE File 
 4. PreSet filename after installation 
 5. PreSet Registry Key 
 6. PreSet Autostart Method: 
 Registry: Run 
 Registry: RunSevices 
 Less known method 
 7. PreSet Fake error message 
 8. PreSet Connection Notify Username 
 9. PreSet Connection Notify ICQ# 
 10. PreSet Connection Notify E-Mail 
 11. PreSet Connection Notify IRC Chan. 
 12. PreSet IRC Port 
 13. Change Server *.exe Icon


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