DonaldD.Trojan

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Discovered: September 28, 1999
Updated: February 13, 2007 11:51:32 AM
Type: Trojan Horse


The DonaldD.Trojan is similar to the BackOrifice.Trojan. When installed in Microsoft Windows, this backdoor Trojan horse program enables others to gain full access to the system through a network connection. It consists of two parts: a server application and a client application. Both applications can run under Windows 95, 98, and NT 4.0. The client application, running on one computer, may be used to monitor and control a second computer running the server application.

The port number through which the client controls the server is configurable. However, as long as the port is blocked by a firewall, this Trojan horse will not be able to infiltrate the server. It does not matter whether the TCP or SPX protocol is implemented. There have not been any reports of this program being able to break through a firewall.

Antivirus Protection Dates

  • Initial Rapid Release version September 28, 1999
  • Latest Rapid Release version March 23, 2017 revision 037
  • Initial Daily Certified version September 28, 1999
  • Latest Daily Certified version March 23, 2017 revision 041

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

Writeup By: Motoaki Yamamura

Discovered: September 28, 1999
Updated: February 13, 2007 11:51:32 AM
Type: Trojan Horse


The server application may be configured with several different options.
The networking protocol may be TCP or SPX. Any port number between 1 and 65535 may be selected for communication. The default port number for TCP is 23476, and an additional default port is 23477. For SPX, it is 0x9014 and an additional default port is 0x9015.

A password may be specified to limit the access on a server. However, there is a bug in version 1.52 of the Trojan. In the client GUI, the password typed in is initially hashed using MD5 and is converted to a 32-byte string, which is the hex representation. Then the result is sent to the server. For the command-line version of the client, the password is sent without using any type of encryption. Thus, if a user sets the password of the server using the command-line client, then they cannot access it again by using the GUI client with the same password.

Additional bugs found in version 1.52 of this Trojan:

  • When the client attempts to play a .wav file to the server, and the client does not specify a file name in this field, the client program crashes.
  • The same situation occurs when the client user forgets to specify the path for the server upgrade command.

The following is a list of commands the client program may send to the server program:
  • Create and delete directories
  • Copy, delete, rename, upload, and download files
  • View, terminate, and set priorities for processes
  • Suspend and resume threads
  • Execute programs
  • Create and delete registry keys
  • Set registry values
  • Modify system date and time
  • Perform a shutdown, logoff, restart, and power-off
  • Obtain a list of windows opened
  • Get a snapshot of the entire screen or just for a specific window
  • Send messages to a specific window
  • Modify CMOS (this currently works only in Windows 95/98)
  • Look at the contents of the buffer where the keyboard input is stored
  • Remap and disable keys of the keyboard
  • Simulate certain keystrokes (only works in Windows 95/98)
  • Open and close the CD-ROM tray
  • Turn the monitor on and off
  • Send message boxes with a few sets of buttons to choose from
  • Play .wav files
  • Chat with other people
  • Obtain CMOS and screen saver passwords
  • Query a list of shared resources


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: Motoaki Yamamura

Discovered: September 28, 1999
Updated: February 13, 2007 11:51:32 AM
Type: Trojan Horse


How you remove this Trojan depends on your version of Windows.

Windows 95/98
If you are running Windows 95/98, then follow these instructions. You will need an uninfected DOS boot disk or a Windows Startup disk.

Run a full system scan
Make sure that you have the most recent virus definitions, and run a full system scan, making sure that Norton AntiVirus (NAV) is set to scan all files. Write down the names of any files infected with the DonaldD.Trojan. Have NAV delete them if possible; in most cases it will not be able to do so. When finished, go on to the next section.

Delete files in DOS
Follow these steps to remove any infected files that could not be deleted by NAV:

    1. Shut down Windows, turn off the power, and then wait thirty seconds. Do not simply press the reset button.
    2. Insert a clean DOS boot disk or Windows Startup disk into the floppy disk drive.
    3. Restart the computer. It will boot to a DOS prompt.
    4. Type the following, and then press Enter:

      cd \windows\system

      NOTE: If Windows is installed in a folder other than C:\Windows, change the prededing command accordingly.
    5. Type the following, and then press Enter:

      del <filename>

      where <filename> is the name of the file that you wrote down when you ran the scan. For example, if NAV found an infected file named Badthing.exe, then type del badthing.exe
    6. Remove the floppy disk, and then restart the computer.

    Edit the Windows registry
    Follow these steps to remove a registry entry that was added by the Trojan:

    CAUTION: We strongly recommend that you back up the system registry before making any changes to it. Incorrect changes to the registry may result in permanent data loss or corrupted files. Be sure to modify the specified keys only. See the document How to back up the Windows registry before proceeding.
    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 and select the following subkey:

      HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\VMLDR
    4. Press Delete, and then click Yes to confirm.
    5. Click the Registry menu, and click Exit to save the changes and close the Registry Editor.

    Windows NT

    If you are running Windows NT, then follow these instructions. You will need an uninfected DOS boot disk or a Windows Startup disk.

    Run a full system scan
    Make sure that you have the most recent virus definitions, and run a full system scan, making sure that Norton AntiVirus (NAV) is set to scan all files. Write down the names of any files infected with the DonaldD.Trojan. Have NAV delete them if possible; in most cases it will not be able to do so. When finished, go on to the next section.

    Edit the Windows registry
    Follow these steps to remove a registry entry that was added by the Trojan:

    CAUTION: We strongly recommend that you back up the system registry before making any changes to it. Incorrect changes to the registry may result in permanent data loss or corrupted files. Be sure to modify the specified keys only. See the document How to back up the Windows registry before proceeding.

    NOTE: You must be logged on as Administrator.
    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 and select the following subkey:

      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
    4. In the right pane, double-click BootExecute.
    5. In the Edit Binary Value box, look for and select the following hexadecimal numbers:

      00 62 6F 6F 74 65 78 65 63

    6. Select these numbers only, and then delete them.
    7. Click OK.
    8. In the right pane, select and delete the following values:

      Pdata0
      Pdata1
    9. Exit the Registry Editor, and then restart the computer.

    Delete files
    Use Find Files to locate and delete any files that NAV could not delete.


Writeup By: Motoaki Yamamura