Backdoor.Hupigeon

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Discovered: October 09, 2002
Updated: February 13, 2007 11:55:22 AM
Also Known As: Backdoor.Hupigeon [AVP]
Type: Trojan Horse
Systems Affected: Windows


Backdoor.Hupigeon is a Backdoor Trojan that gives an attacker unauthorized access to an infected computer. It is written using the Delphi programming language and packed with UPX.

Antivirus Protection Dates

  • Initial Rapid Release version October 09, 2002
  • Latest Rapid Release version July 22, 2019 revision 024
  • Initial Daily Certified version October 09, 2002 revision 007
  • Latest Daily Certified version July 20, 2019 revision 002
  • Initial Weekly Certified release date October 09, 2002

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


Technical Description


When Backdoor.Hupigeon runs, it performs the following actions:

It copies itself as:
%system%\Winndow386.exe
%windows%\N0tepad.exe

NOTES:

  • %windir% is a variable. The Trojan locates the Windows installation folder (by default this is C:\Windows or C:\Winnt) and copies itself to that location.
  • %system% is a variable. The Trojan 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)

It creates the value

winndow386    %system%\Winndow386.exe

in the registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunService
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

so that the Trojan starts when you start or restart Windows.

It modifies the value

(Default)    %windows%\N0tepad.exe %1

in the registry keys

HKEY_CLASSES_ROOT\txtfile\shell\open\command
HKEY_CLASSES_ROOT\inifile\shell\open\command

It modifies the value

(Default)    %system%\Winndow386.exe %1 %*

in the registry key

HKEY_CLASSES_ROOT\exefile\shell\open\command

As a result of these modifications, the Trojan will start anytime that you open a .txt file, or run a .exe or .ini file.

The Trojan allows the hacker to do any of the following:
  • Enable/disable the Trojan
  • Open/close CD-ROM drive
  • Steal ICQ configurations
  • Steal system information
  • Log keystrokes


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.


Removal


NOTES:

  • These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
  • If the Trojan has successfully modified the registry, most programs, including Symantec antivirus software or LiveUpdate, will not run. In this case, first follow the instructions in the section To edit the registry so that you can run .exe files, which follows.
  1. Update the virus definitions
  2. Run a full system scan, and delete all files that are detected as Backdoor.Hupigeon.
  3. Reverse the changes that the Trojan made to the registry.

For details on how to do this, read the following instructions.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions 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 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.

To scan for and delete the infected files:
  1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
  2. Run a full system scan.
  3. If any files are detected as infected with Backdoor.Hupigeon, click Delete.

To delete 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.
  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 key

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunService
  4. In the right pane, delete the value

    winndow386    %system%\Winndow386.exe
  5. Navigate to the key

    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    In the right pane, delete the value

    winndow386    %system%\Winndow386.exe
  6. Exit the Registry Editor.

To edit the registry so that you can run .exe (and other) files
If the Trojan has successfully modified the registry, most programs, including Symantec antivirus software or LiveUpdate will not start. In this case, first follow the instructions in this section and then start over at the beginning of the removal instructions.

To copy Regedit.exe to Regedit.com:
Because the worm modified the registry so that you cannot run .exe files, you must first make a copy of the Registry Editor as a file with the .com extension, and then run that file.
  1. Do one of the following, depending on which version of Windows you are running:
    • Windows 95/98 users: Click Start, point to Programs, and click MS-DOS Prompt. A DOS window opens at the C:\Windows prompt. Go on to step 2 of this section.
    • Windows Me users: Click Start, point to Programs, point to Accessories, and then click MS-DOS Prompt. A DOS window opens at the C:\Windows prompt. Go on to step 2 of this section.
    • Windows NT/2000 users:
      1. Click Start, and click Run.
      2. Type the following and then press Enter:

        command

        A DOS window opens.
      3. Type the following, and then press Enter:

        cd \winnt
      4. Go on to step 2 of this section.
    • Windows XP:
      1. Click Start, and click Run.
      2. Type the following, and then press Enter:

        command

        A DOS window opens.
      3. Type the following, and then press Enter after typing each one:

        cd\
        cd \windows
      4. Proceed to step 2 of this section.
  2. Type the following, and then press Enter:

    copy regedit.exe regedit.com
  3. Type the following, and then press Enter:

    start regedit.com

    The Registry Editor will open in front of the DOS window. After you finish editing the registry, exit the Registry Editor, and then exit the DOS window, as well.
1. Proceed to the next section, "To edit the registry and remove keys and changes made by the worm," only after you have performed the previous steps.


NOTES:
  • The Registry Editor will open in front of the DOS window. After you finish editing the registry and have closed the Registry Editor, then close the DOS window, as well.
  • After BackDoor.Subseven has been successfully removed, then you may delete the Regedit.com file.


To edit 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. Navigate to and select the following key:

    HKEY_CLASSES_ROOT\exefile\shell\open\command

    CAUTION: The HKEY_CLASSES_ROOTkey contains many subkey entries that refer to other file extensions. One of these file extensions is .exe. Changing this extension can prevent any files ending with an .exe extension from running. Make sure that you browse all the way along this path until you reach the \command subkey.

    Modify the HKEY_CLASSES_ROOT\exefile\shell\open\command subkey that is shown in the following figure:

    <<=== NOTE: Modify this key.
  2. In the right pane, double-click the (Default) value.
  3. Delete the current value data, and then type: "%1" %* (That is, type the following characters: quote-percent-one-quote-space-percent-asterisk.)

    NOTES:
    • Under Windows 95/98/Me/NT, the Registry Editor automatically encloses the value within quotation marks. When you click OK, the (Default) value should look exactly like this:

      ""%1" %*"  
    • Under Windows 2000/XP, the additional quotation marks will not appear. When you click OK, the (Default) value should look exactly like this:

      "%1" %*
    • Make sure that you completely delete all value data in the command key before you type the correct data. If you leave a space at the beginning of the entry, any attempt to run program files will result in the error message, "Windows cannot find .exe." If this happens to you, start over at the beginning of this document, and make sure that you completely remove the current value data.
  4. Navigate to and select the key

    HKEY_CLASSES_ROOT\txtfile\shell\open\command
  5. In the right pane, double-click the (Default) value.
  6. Delete the current value data, and replace it with the correct value for your version of Windows.

    NOTE: This value varies with the version of Windows and, on some systems, the installation path. You may need to look at that same key on a working computer that has the same version of Windows and configuration to determine this. Two common values are:
    • Windows 98: C:\Windows\Notepad.exe %
    • Windows 2000: %SystemRoot%\system32\NOTEPAD.EXE %1
  7. Navigate to and select the key

    HKEY_CLASSES_ROOT\inifile\shell\open\command
  8. In the right pane, double-click (Default).
  9. Delete the current value data, and replace it with the correct value for your version of Windows.

    NOTE: This value varies with the version of Windows and, on some systems, the installation path. You may need to look at that same key on a working computer that has the same version of Windows and configuration to determine this. Two common values are:
    • Windows 98: C:\Windows\Notepad.exe %
    • Windows 2000: %SystemRoot%\system32\NOTEPAD.EXE %1
  10. Leave the Registry Editor open and start over at the beginning of the Removal instructions.



Writeup By: Kaoru Hayashi