Discovered: June 26, 2002
Updated: February 13, 2007 12:00:06 PM
Also Known As: Backdoor.Trojan, Trojan.Win32.Anakha.b, BackDoor-UY, Troj/Anaka-B
Type: Trojan Horse
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP
Update the virus definitions, run a full system scan, and delete all files that Norton AntiVirus (NAV) detects as Backdoor.Anakha.
- Delete C:\%System%\Rundll32.pin.
- Delete the value
ShellEx C:\%System%\ShellEx.exe
from the registry key
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
For details on how to do this, read the following instructions.
To scan with Norton AntiVirus and delete the infected files:
- Obtain the most recent virus definitions. There are two ways to do this:
- Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
- Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
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.
- Start Norton AntiVirus (NAV), and make sure that it is configured to scan all files.
- Run a full system scan.
- Delete all files that NAV detects as Backdoor.Anakha.
- (Optional) Using Windows Explorer, delete C:\%System%\Rundll32.pin.
To remove the value from the registry:
CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document
How to make a backup of the Windows registry for instructions.
- Click Start, and click Run. The Run dialog box appears.
- Type regedit and 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
ShellEx C:\%System%\ShellEx.exe
- Click Registry, and click Exit.
Writeup By: Yana Liu