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Discovered: March 27, 2003
Updated: February 13, 2007 11:44:59 AM
Type: Worm
Systems Affected: Windows

W32.Kwbot.E.Worm attempts to spread across the file-sharing networks, such as KaZaA and iMesh. The worm also has a Backdoor Trojan capability that allows a hacker to control your computer. W32.Kwbot.E.Worm is packed with ASPack v2.12.

W32.Kwbot.E.Worm is a variant of W32.Kwbot.Worm .

Antivirus Protection Dates

  • Initial Rapid Release version March 27, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version March 27, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date April 02, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

When W32.Kwbot.E.Worm runs, it performs the following actions:

  1. Copies itself as %System%\Dllmem32.exe.

    %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).
  2. Does one of the following, depending on the operating system:
    • If the operating system is Windows NT/2000/XP, the worm changes the value to:

      Shell    Explorer.exe %system%\dllmem32.exe

      in the registry key:

      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

      so that the worm runs when you start Windows.
    • If the operating system is Windows 98/Me, the worm creates the value:

      DLL32    dllmem32.exe

      in the following registry keys:


      so that the worm runs when you start Windows.

  3. If the operating system is Windows 95/98/Me, the worm registers itself as a service process, so that it is not displayed in the Close Program dialog box.
  4. Checks for an Internet connection every 30 seconds. As soon W32.Kwbot.E.Worm detects one, it connects to a specific IRC server using port 6667, joins a specific channel, and notifies a hacker by sending him/her a private message. Then, the worm waits for the commands that the hacker transmits using IRC. The commands allow the hacker to perform any of the following actions:
    • Deliver system and network information to the hacker.
    • Manage the self installation.
    • Download and execute files.
    • Perform Denial of Service (DoS) attacks.
    • Replicate across file-sharing networks, such as KaZaA and iMesh.

How W32.Kwbot.E.Worm spreads

NOTE: For W32.Kwbot.E.Worm to spread, it requires that the KaZaA or iMesh software be installed on the computer.

To spread across the KaZaA and iMesh file-sharing networks, the W32.Kwbot.E.Worm performs the following actions:
  1. Creates the folder %Windir%\CTemp32.
  2. Copies itself to the %Windir%\CTemp32 folder as the following filenames:
    • Active webcam 3.4 crack.exe
    • Coffeecup webcam 3.5 crack.exe
    • Biromsoft WebCam 3.01 crack.exe
    • SpyCast Webcam Studio 1.1.8 crack.exe
    • ISpy WebCam 2.0 crack.exe
    • Webcam Uploader 2001 3.1 crack.exe
    • WebCam-Control-Center 6.0 crack.exe
    • CamShot Webcam HTTP Server 2.5 crack.exe
    • WebCam Recorder 1.22 crack.exe
    • Creditcard number generator.exe
    • Hotmail account cracker.exe
    • Yahoo account cracker.exe
    • Winzip crack/serial.exe
    • Winrar crack.exe
    • Getright 5.0 crack.exe
    • Guard-IE Pop-up Killer Suite 3.2 crack.exe
    • Acoustica MP3 CD Burner crack.exe
    • Norton AntiVirus Definitions Update.exe
    • CoffeeCup HTML Editor 9.5 crack.exe
    • pop up stopper.exe
    • Dreamweaver MX crack.exe
    • Turbo Browser 10th Gold Edition 9.0 crack.exe
    • Internet Download Manager 3.13 crack.exe
    • Nero Burning ROM crack.exe
    • Opera 7.02 crack.exe
    • Alchemy Network Monitor 4.7.5 crack.exe
    • Chess Rally 2.45 crack.exe
    • Logbook Pro 1.9.3 crack.exe
    • Zone alarm pro crack.exe
    • SolarCell 1.3 crack.exe
    • Spytech SecurityWorks 2003 crack.exe
    • WebCompiler 2000 1.67 crack.exe
    • Accel SpeedTec 2.1.194 crack.exe
    • BigJig 7.0 crack.exe
    • Cygwin 1.3.17 crack.exe
    • ShortKeys Lite 1.7 crack.exe
    • Table Tennis Pro 1.3 crack.exe
    • The Bat 1.62 crack.exe
    • Tweakmaster 1.7 crack.exe
    • BlackWidow 4.37 crack.exe
    • DLL Show 5.0 crack.exe
    • PolyView 3.86 crack.exe
    • PowerStrip 3.3 crack.exe
    • SereneScreen Marine Aquarium 1.1.2 crack.exe
    • UltraEdit-32 9.2 crack.exe
    • McAfee VirusScan Home Edition 7.0 crack.exe
    • Talisman Desktop 2.5 crack.exe
    • Mcafee firewall crack.exe
    • FTP Voyager crack.exe
    • VisualRoute 7.1c .exe
    • Media Jukebox 8.0.394 crack.exe
    • Axialis AX-CDPlayer 2.61 crack.exe
    • AirStrike 3D: Operation W.A.T. 1.2 crack.exe
    • ZBrush 1.55 crack.exe
    • Ulead Photo Explorer 8.0 crack.exe
    • AutoMate crack.exe
    • ActiveSkin 4.27 crack.exe
    • Sound Forge 6.0d build 219 crack.exe
    • WinProxy 4.0i crack.exe
    • BlackICE PC Protection 3.5 crack.exe
    • IrfanView 3.8 crack.exe
    • NoteTab Pro 4.92 crack.exe
    • Window Washer 4.8 crack.exe
    • Bugatron 1.18 crack.exe
    • FtpTree ActiveX Control 9.1 crack.exe
    • QuakeMap World Edition 2.1 crack.exe
    • Unreal tournament 2003 keygen.exe
    • Pornsite password cracker (works).exe
    • Nokia hacker.exe
    • Cellular hacker.exe

  3. Adds the values:

    Dir? 012345:%windows%\CTemp32
    DisableSharing       0

    NOTE: "?" in these values represents a number that the worm has chosen.

    to these registry keys:


    so that other KaZaA or iMesh users may download the files from the %Windir%\CTemp32 folder.


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.


The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions.
  2. Do one of the following:
    • Windows 95/98/Me: Restart the computer in Safe mode.
    • Windows NT/2000/XP: End the Trojan process.
  3. Run a full system scan and delete all the files detected as W32.Kwbot.E.Worm.
  4. Reverse the changes that the worm made to the registry.
For details on each of these steps, read the following instructions.

1. 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.

2. Restarting the computer in Safe mode or ending the Trojan process
    Windows 95/98/Me
    Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document, "How to start the computer in Safe Mode."

    Windows NT/2000/XP
    To end the Trojan process:
    1. Press Ctrl+Alt+Delete once.
    2. Click Task Manager.
    3. Click the Processes tab.
    4. Double-click the Image Name column header to alphabetically sort the processes.
    5. Scroll through the list and look for Dllmem32.exe.
    6. If you find the file, click it, and then click End Process.
    7. Exit the Task Manager.
3. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with W32.Kwbot.E.Worm, click Delete.

4. Reversing the changes made to the registry

: 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.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)
  3. Navigate to the key:

  4. In the right pane, delete the value:

    DLL32    dllmem32.exe
  5. Navigate to the key:

  6. In the right pane, delete the value:

    DLL32    dllmem32.exe
  7. Navigate to the key:

  8. In the right pane, delete the value:

    DLL32    dllmem32.exe
  9. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon

    This key does not exist on all the systems. If you do not find it, proceed to the next step.
  10. In the right pane, double-click Shell.
  11. Change the text in the Value data box so that it only reads: Explorer.exe.
  12. Navigate to each of the keys:

  13. In the right pane, delete any values that refer to the %Windir%\CTemp32 folder. For example:

    Dir? 012345:%windows%\CTemp32

    NOTE: "?" in this value represents a number that the worm has chosen.
  14. Exit the Registry Editor.

Writeup By: Serghei Sevcenco