Threat Description

Backdoor:​W32/​SubSeven

Details

Aliases: Backdoor:W32/SubSeven, SubSeven, Backdoor.SubSeven
Category: Malware
Type: Backdoor
Platform: W32

Summary


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



Removal


Automatic action

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

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.



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.

Execution

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.

Activity

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     
Controllers   --------------   
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   Win.ini   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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