W32.Kitro.D.Worm

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Discovered: July 08, 2002
Updated: February 13, 2007 11:58:02 AM
Also Known As: W32.Banegra.int, W32.Kitro.D.int
Type: Worm
Systems Affected: Windows


W32.Kitro.D.Worm is a worm that can spread using email messages and over the Kazaa network. This worm also inserts a Visual Basic Script (VBS) on the system. Due to bugs in the code the mass-mailing routine will not be executed.

NOTE: Definitions prior to July 10, 2002 may detect this threat as W32.Banegra.int or W32.Kitro.D.int.

Antivirus Protection Dates

  • Initial Rapid Release version July 08, 2002
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version July 08, 2002
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 08, 2002

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

Writeup By: Neal Hindocha

Discovered: July 08, 2002
Updated: February 13, 2007 11:58:02 AM
Also Known As: W32.Banegra.int, W32.Kitro.D.int
Type: Worm
Systems Affected: Windows


When W32.Kitro.D.Worm is executed, it does the following:

It creates many copies of itself on the hard drive. It creates nine copies in the %Windir% folder, and it inserts a VBS file under the root of the C: drive.
The VBS file will be named BanderaNegra.VBS.

NOTE: %Windir% is a variable. The worm locates the \Windows folder (by default this is C:\Windows or C:\Winnt) and copies itself to that location.

Next, the worm attempts to email everyone in the Windows Address Book (WAB). In addition, it will collects email addresses of the user's MSN messenger contacts from the registry key

HKEY_CURRENT_USER\Software\Microsoft\MessengerService\ListCache\.NET Messenger Service

and attempts to send itself through the SMTP server mail.hotmail.com.

It will also try to locate SMTP servers in the Windows registry and attempt to send the viral emails through them aswell.

NOTE: There are some bugs in the emailing routine, and therefore the worm may fail to send itself.

W32.Kitro.D.Worm also attempts to spread through the Kazaa peer-to-peer network. It tries to read the registry value

HKEY_CURRENT_USER\Software\Kazaa\Transfer\DlDir0

and if it can do so, it copies itself to the Kazaa share, thus making itself available for other Kazaa users to download.

In order to evade detection by some antivirus products, W32.Kitro.D.Worm manipulates data files and registry information. It modifies the registry value

HKEY_LOCAL_MACHINE\SOFTWARE\KasperskyLab\SharedFiles\Folder

to point to the windows directory and alters the value

PAV.EXE     C:\WINDOWS

in the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

probably in an attempt to prevent an antivirus program from running on startup.

In addition it deletes the following files if they are present on the system:

  • C:\Archiv~1\Perav\Pav.dll
  • C:\Archiv~1\Perav\Per.dll
  • C:\Program Files\Perav\Pav.dll
  • C:\Program Files\Perav\Per.dll

and also the following files from the \Windows folder:
  • Pav.exe
  • \Bases\Avp.set
  • \System\Vshield.vxd
  • \System32\Vshield.vxd
  • \Vshield.vxd

The Visual Basic Script (VBS) that the worm inserted, BanderaNegra.vbs, will email everyone in the Windows Address Book if it is executed. However, the worm does not appear to execute this VBS script.

Recommendations

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.

Writeup By: Neal Hindocha

Discovered: July 08, 2002
Updated: February 13, 2007 11:58:02 AM
Also Known As: W32.Banegra.int, W32.Kitro.D.int
Type: Worm
Systems Affected: Windows



NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions, run a full system scan, and delete all files that are detected as W32.Kitro.D.Worm or VBS.Kitro@mm.

    NOTE: If you are unable to delete the files, you should delete the registry value first, reboot the computer, and then attempt to delete the files.
  2. Delete the value that looks similar to

    KAZAACuF, PAV.EXE, Zonavirus and BNexe

    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 for and delete the infected files:
  1. 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.
  2. Start your Symantec antivirus software and make sure that it is configured to scan all files.
  3. Run a full system scan.
  4. If any files are detected as infected by W32.Kitro.D.Worm or VBS.Kitro@mm, click Delete.

    NOTE: If your Symantec antivirus software is unable to delete the files, follow the instructions in the next section to delete the registry value, reboot the computer, and then run a full system scan again.

To remove the values 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.
  1. Click Start, and click Run. The Run dialog box appears.
  2. Type regedit and then click OK. The Registry Editor opens.
  3. Navigate to the following key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  4. In the right pane, locate the value that looks similar to the following example and delete it:

    KAZAACuF, PAV.EXE, Zonavirus and BNexe
  5. Click Registry, and click Exit.


Writeup By: Neal Hindocha