Discovered: April 29, 2003
Updated: February 13, 2007 12:00:40 PM
Also Known As: Backdoor.Assasin.20 [KAV]
Type: Trojan Horse
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP
These instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
- Reverse the changes that the Trojan made to the registry and restart the computer.
- Update the virus definitions.
- Run a full system scan and delete all the files detected as Backdoor.Assasin.F.
- Delete the %System%\IDE folder.
For details on each of these steps, read the following instructions.
1. Reversing the changes that the Trojan made to the registry and restarting the computer
CAUTION: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "
How to make a backup of the Windows registry," for instructions.
- Click Start, and then click Run. (The Run dialog box appears.)
- Type regedit
Then click OK. (The Registry Editor opens.)
- Navigate to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- In the right pane, delete the value:
IDE %System%\IDE\ide.exe
- Navigate to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
RunServices
- In the right pane, delete the value:
IDE %System%\IDE\ide.exe
- Exit the Registry Editor.
- Restart the computer.
2. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
- Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
- Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).
The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
3. Scanning for and deleting the infected files
- Start your Symantec antivirus program and make sure that it is configured to scan all the files.
- Run a full system scan.
- If any files are detected as infected with Backdoor.Assasin.F, click Delete.
4. Deleting the %System%\IDE folder
- Open Windows Explorer.
- Navigate to the %System% folder.
NOTE: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
- Locate the folder named IDE, right-click it, and choose Delete.
- Close Windows Explorer.
Writeup By: Robert X Wang