PrettyPark.Worm

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Discovered: May 28, 1999
Updated: February 13, 2007 11:48:30 AM
Also Known As: Trojan Horse, W32.PrettyPark, Trojan.PSW.CHV, CHV, W32/Pretty.worm.unp, I-Worm.PrettyPark [Kaspersky], W32/Pretty.gen@MM [McAfee], W32/Pretty [Sophos], WORM_PRETTYPARK [Trend]
Type: Worm
Systems Affected: Windows


This worm program behaves similarly to Happy99 Worm. It was originally spread by email. When the attached program file, PrettyPark.exe, is executed, it may display the 3D pipe screen saver.

Once the worm program is executed, it tries to email itself automatically every 30 minutes (or 30 minutes after it is loaded) to email addresses registered in your Internet address book.

It also tries to connect to an IRC server and join a specific IRC channel. The worm sends information to IRC every 30 seconds to keep itself connected, and to retrieve any commands from the IRC channel.

Antivirus Protection Dates

  • Initial Rapid Release version June 04, 1999
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version June 04, 1999
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date June 04, 1999

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

Discovered: May 28, 1999
Updated: February 13, 2007 11:48:30 AM
Also Known As: Trojan Horse, W32.PrettyPark, Trojan.PSW.CHV, CHV, W32/Pretty.worm.unp, I-Worm.PrettyPark [Kaspersky], W32/Pretty.gen@MM [McAfee], W32/Pretty [Sophos], WORM_PRETTYPARK [Trend]
Type: Worm
Systems Affected: Windows


PrettyPark.Worm is a worm that performs similarly to Happy99.Worm. This worm was originally spread through a mass emailing. The program file attached to these email is named PrettyPark.exe. When PrettyPark.exe is executed, it may display the Windows 3D Pipes screen saver. It also does the following:

  • It creates a file named Files32.vxd in the \Windows\System folder .
  • It modifies the (Default) value from "%1" %* to FILES32.VXD "%1" %* in the following registry key:

    HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command
  • It tries to email itself, every 30 minutes, to addresses in your Internet address book.
  • It tries to connect to an IRC server and join a specific IRC channel. If it is successful, the worm sends information to this IRC channel every 30 seconds to keep itself connected and to retrieve any commands. By using IRC, the author or distributor of the worm can access information on your system including:
    • Computer name
    • Product name
    • Product identifier
    • Product key
    • Registered owner
    • Registered organization
    • System root path
    • Version number
    • ICQ identification numbers
    • ICQ nicknames
    • Your email address
    • Dial-Up networking user name and passwords

    In addition, being connected to IRC opens a security hole in which your computer can potentially be used to receive and execute files.


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.

Discovered: May 28, 1999
Updated: February 13, 2007 11:48:30 AM
Also Known As: Trojan Horse, W32.PrettyPark, Trojan.PSW.CHV, CHV, W32/Pretty.worm.unp, I-Worm.PrettyPark [Kaspersky], W32/Pretty.gen@MM [McAfee], W32/Pretty [Sophos], WORM_PRETTYPARK [Trend]
Type: Worm
Systems Affected: Windows


Automatic removal instructions
The easiest way to remove this worm is to use the Fix PrettyPark.Worm tool .

Manual removal instructions
To remove this worm, please follow the instructions in each section. We strongly recommend that you read and understand the entire procedure before proceeding.

PrettyPark.Worm comprises two files: PrettyPark.exe and Files32.vxd. It also adds a registry key that loads PrettyPark.exe whenever an executable program is launched. To remove this worm, you must first change the Windows registry so it will not run the virus program; then you must delete the PrettyPark.exe file.

NOTE: The procedure described in this document is complex and assumes that you are familiar with basic Windows and DOS procedures. If you are not, then we suggest that you obtain the services of a computer consultant.

If you cannot start Windows
If you cannot start Windows 95/98/2000 at all, then you must start Windows in Safe Mode. Once Windows is in Safe Mode:

  • If you cannot run program files, proceed to the next section.
  • If you can run program files, skip to the section titled Edit the registry.

Follow these steps to start Windows 95/98/2000 in Safe Mode:

NOTE: In Safe Mode, Windows uses default settings: VGA monitor, no network, Microsoft mouse driver, and the minimum device drivers required to start Windows. You will not have access to CD-ROM drives, printers, or other devices.
  • Windows 95:
    1. Exit all programs.
    2. Click Start, and click Shut Down. The Shut Down Windows dialog box appears.
    3. Click Shut Down, and then click OK.
    4. Click Yes to confirm the shutdown.
    5. Turn off the computer (if necessary) and wait 30 seconds.

      NOTE: You must turn off the power to remove the virus from memory. Do not use the reset button.
    6. Turn on the power.
    7. When "Starting Windows 95..." appears on the screen, press F8. The Windows 95 Startup Menu appears.
    8. Select Safe Mode and press Enter. Windows starts in Safe Mode.
  • Windows 98:
    1. Click Start, and click Run.
    2. Type msconfig and click OK. The System Configuration Utility dialog box appears.
    3. Click Advanced on the General tab.
    4. Check Enable Startup Menu, click OK, and then click OK again.
    5. Exit all programs.
    6. Click Start, and click Shut Down. The Shut Down Windows dialog box appears.
    7. Click Shut Down, and then click OK.
    8. Click Yes to confirm the shutdown.
    9. Turn off the computer and wait 30 seconds.

      NOTE: You must turn off the power to remove the virus from memory. Do not use the reset button.
    10. Turn on the computer and wait for the Windows 98 Startup menu.
    11. Select Safe Mode, and then press Enter. Windows will start in Safe Mode.

      NOTE: (Optional) When you have completed all of the procedures in this document, you can disable the Startup Menu, if desired. To do so, return to this section and then follow these steps:
      1. Click Start, and click Run.
      2. Type msconfig and click OK. The System Configuration Utility dialog box appears.
      3. Click Advanced on the General tab.
      4. Uncheck Enable Startup Menu, click OK, and then click OK again.
      5. Restart the computer.
  • Windows 2000:
    1. Exit all programs.
    2. Click Start, and click Shut Down. The Shut Down Windows dialog box appears.
    3. Click Shut Down, and then click OK.
    4. Click Yes to confirm the shutdown.
    5. Turn off the computer and wait 30 seconds.

      NOTE: You must turn off the power to remove the virus from memory. Do not use the reset button.
    6. Turn on the computer.
    7. As the computer restarts, you will see a continuous line along the bottom of the screen that looks similar to |||||||||||||||||||||||||||||. Beneath this line you will see the text, "For trouble-shooting and advanced startup options for Windows 2000, press F8." Immediately press F8.
    8. Select Safe Mode, and then press Enter. Windows will start in Safe Mode.

If you cannot run program files
If you cannot run program files because you have already deleted the Files32.vxd file, then follow the procedure for the version of Windows that you are running. Otherwise, go on to the next section.
  • Windows 95/98
  1. Click Start, point to Programs, and click MS-DOS Prompt.
  2. Type copy regedit.exe regedit.com and then press Enter.
  3. Type start regedit.com and then press Enter.
  4. Proceed to the Edit the registry section.

    NOTE: The Registry Editor will open in front of the DOS window. After you have finished editing the registry, and have closed the Registry Editor, close the DOS window.
  • Windows NT/2000
  1. Click Start, point to Find, and click Files or Folders.
  2. Make sure that "Look in" indicates the drive on which Windows is installed.
  3. Type regedit.exe in the Named box, and click Find Now.
  4. Right-click the Regedit.exe file in the results pane, and click Copy.
  5. Close the Find dialog box.
  6. Right-click the Windows desktop, point to New, and click Folder. Type a name for the folder, such as RegFix, and then press Enter.
  7. Double-click the folder you just created to open it, click the Edit menu, and click Paste. This will place a copy of Regedit.exe in the folder.
  8. Click the View menu, and click Options. The Options dialog box appears.
  9. Click the View tab, and make sure that "Hide file extensions for known file types" is not checked. Click OK.
  10. Right-click the copy of the Regedit.exe file, and click Rename.
  11. Change Regedit.exe to Regedit.com, and then press Enter. Click Yes to confirm the change.
  12. Double-click the Regedit.com file to start the Registry Editor, and then proceed to the Edit the registry section.
    NOTE: After PrettyPark.Worm has been successfully removed, you may delete the Regedit.com file.

    Edit the registry

    CAUTION : We strongly recommend that you back up the Windows registry before making any changes. Incorrect changes to the registry can result in permanent data loss or corrupted files. Please make sure you modify only the keys specified in this document. For more information about how to back up the registry, please read How to back up the Windows registry before proceeding with the following steps. If you are concerned that you cannot follow these steps correctly, then please do not proceed. Consult a computer technician for more information.

    If you are confident that you can complete the following steps without error, then please proceed with caution, keeping in mind all warnings you have read.
    1. Start the Registry Editor if necessary:
      • If you have performed the procedure in the previous section, the Registry Editor is already open. Skip to step 4.
      • If it was not necessary to perform the procedures in the previous section, go on to step 2.
    2. Click Start, and click Run. The Run dialog box appears.
    3. Type regedit and click OK. The Registry Editor opens.
    4. Navigate to and open the following key:

      HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command

      Important Warning!
      The \Classes subkey 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 a .exe extension from running. Make sure you browse all the way along this path until you reach the \command subkey.
      Do not
      modify the HKEY_LOCAL_MACHINE\Software\Classes\.exe key.
      Do modify the HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command subkey that is shown in the following figure.

      <<=== NOTE: This is the key that you need to modify.

    5. Double-click the (Default) value in the right pane.
    6. Delete the current value data, and then type "%1" %* (quote-percent-one-quote-space-percent-asterisk).

      NOTE: The Registry Editor will automatically enclose the value within quotation marks. When you click OK, the (Default) value should look exactly like this:

      ""%1" %*"

      Make sure you completely delete all value data in the command key before typing the correct data. If a space is left accidentally 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, making sure to completely remove the current value data.
    7. Close the Registry Editor, and perform a full system scan with Norton AntiVirus to completely remove all traces of the PrettyPark.Worm program files.
    8. Restart the computer.
    To delete the PrettyPark.Worm program files
    1. Click Start, point to Find, and click Files or Folders.
    2. Make sure that "Look in" is pointing your hard drive, or all drives if this is an option.
    3. Type files32.vxd in the Named box, and then click Find Now.
    4. Delete any copies that appear.
    5. Make sure that "Look in" is pointing your hard drive, or all drives if this is an option.
    6. Type pretty*.exe in the Named box, and then click Find Now.
    7. Delete any copies that appear.

      NOTE: If Norton AntiVirus is installed and running on this computer, you may be alerted that the files are infected when you complete the previous steps. If that happens, choose Delete and ignore any subsequent Windows messages that say that the file cannot be deleted. (This is Windows alerting you that it cannot find the specified file. It cannot find the file because it has already been deleted by Norton AntiVirus.)
    8. Delete the file PrettyPark.exe.
    9. Restart the computer.