Backdoor.SubSeven is a Trojan horse, similar to Netbus or Back
Orifice. It enables unauthorized people to access your computer over
the Internet without your knowledge. When the server portion of the
program is running on a computer, it is possible for the person who is
accessing the computer remotely to do the following:
Set it up as an FTP server
Browse files on that system
Take screen shots
Capture real-time screen information
Open and close programs
Edit information in currently running programs
Show pop-up messages and dialog boxes
Hang up a dial-up connection
Restart a computer remotely
Open the CD-ROM
Edit registry information
-------------------------------------
When it is run, BackDoor.Subseven makes the following changes to the
system:
Drops (adds) a copy of itself and a randomly named executable file,
such as Eutccec.exe, to the \Windows or \Windows\System folder.
Adds the dropped file to the load= and run= lines of the Win.ini file.
Adds the dropped file name to the shell=explorer.exe line of the
System.ini file.
Creates the WinLoader value and sets it equal to the dropped file name
in the following registry keys.
Modifies the (Default) value from "%1" %* to, for example, eutccec.exe
"%1" %* in the following registry keys:
HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
----------------------------------
To remove BackDoor.Subseven, follow these steps:
NOTE: These removal instructions are for versions of BackDoor.Subseven
that are currently being seen by Symantec Technical Support virus
removal technicians. The original version of BackDoor.Subseven did not
have the random file name behavior, and made different changes to the
system. Although Symantec Technical Support has not received reports
in some time for the original version, with its somewhat different
behavior it is still possible that it exists, and that unprotected
computers could be infected by it. If the information in this document
does not fit your situation, then see the section at the end of the
Removal Instructions section titled Removal instructions for older
versions of Backdoor.Subseven.
To remove Backdoor.Subseven do the following:
Run LiveUpdate to make sure that you have the most recent definitions.
Run a full system scan, making sure that NAV is set to scan all files.
Make a copy of the Regedit.exe file with the .com extension (if
necessary).
Remove the references added to the Win.ini and System.ini files.
(Windows 95/98/Me computers).
Remove the references added to the Windows registry.
-------------------------------------------------
Removal instructions for older versions of Backdoor.SubSeven
CAUTION: Follow these instructions only if the instructions in the
previous sections did not remove the Trojan.
To remove this Trojan, you need to do the following:
1. Restart the computer in Safe mode.
2. Remove the following registry key that was placed there by the
Trojan:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\System
Traylcon
3. Restart in MS-DOS mode, and then delete the
\Windows\Systemtrayicon.exe file.
4. Restart Windows, and then rename the Watching.dll file.
The details for each of these steps follows:
Restart the computer in Safe mode
Before you edit the registry, you need to restart Windows in Safe
mode. This can take several minutes.
NOTE: In Safe mode, Windows uses default settings: VGA monitor, no
network, Microsoft mouse driver, and the minimum device drivers
required to start Windows. You will not have access to CD-ROM drives,
printers, or other devices.
Windows 95:
1. Exit all programs.
2. Click Start, and then click Shut Down. The Shut Down Windows dialog
box appears.
3. Click Shut Down, and then click OK.
4. Click Yes to confirm the shut down.
5. Turn off the computer (if necessary) and wait 30 seconds.
NOTE: You must turn off the power to remove the virus from memory. Do
not use the Reset button.
6. Turn on the computer.
7. When "Starting Windows 95..." appears on the screen, press F8. The
Windows 95 Startup Menu appears.
8. Press the number that corresponds to Safe mode, and then press
Enter. Windows will start in Safe mode.
Windows 98:
1. Click Start, and then click Run.
2. Type msconfig and then click OK. The System Configuration Utility
dialog box appears.
3. Click Advanced on the General tab.
4. Check Enable Startup Menu, click OK, and then click OK again.
5. Exit all programs.
6. Click Start, and then click Shut Down. The Shut Down Windows dialog
box appears.
7. Click Shut Down, and then click OK.
8. Click Yes to confirm the shut down.
9. Turn off the computer and wait 30 seconds.
NOTE: You must turn off the power to remove the virus from memory. Do
not use the Reset button.
10. Turn on the computer, and wait for the Windows 98 Startup menu.
11. Press the number that corresponds to Safe mode, and then press
Enter. Windows will start in Safe mode.
Edit the registry
Follow these steps to remove the entry that the Trojan placed in the
registry:
CAUTION: We strongly recommend that you back up the system registry
before making any changes. Incorrect changes to the registry could
result in permanent data loss or corrupted files. Please make sure you
modify only the keys specified. Please see the document How to Back Up
the Windows 95/98/NT Registry before proceeding.
1. Click Start, and then click Run.
2. Type regedit and then press Enter.
3. Navigate to and select the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
4. In the right pane, select SystemTrayIcon, press Delete, and then
click Yes to confirm.
------------------------------------------------------ |