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Updated: February 13, 2007 11:51:21 AM
Also Known As: Net.666, Explore666
Type: Virus

This virus infects Windows .exe files, including 9x and NT. The virus creates infected files on the system and attempts to infect other Windows executables. The virus attempts to ping four different IP addresses believed to be located in New Zealand. It then opens a port, allowing remote-control access. The virus also attempts to modify the registry to execute the virus on startup. There are several variants of this virus, which have been found previously in the wild.

Antivirus Protection Dates

  • Initial Rapid Release version February 10, 1998
  • Latest Rapid Release version February 10, 1998
  • Initial Daily Certified version February 10, 1998
  • Latest Daily Certified version February 10, 1998

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

Writeup By: Eric Chien

Updated: February 13, 2007 11:51:21 AM
Also Known As: Net.666, Explore666
Type: Virus

This virus is a prepending PE infector, which replicates under 9x and NT. The virus infects the files Notepad.exe and Setup.exe, and creates clean backups of these files as Notepadx.exe and Setupx.exe.
The virus creates the files Winipx.exe, Winipxa.exe, and Winsrvc.exe in the Windows directory.
The virus adds the following registry entries:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices\WINIPX = C:\Windows\Winipx.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon\Shell=Explorer.exe, Winipx.exe

Winipx.exe is created in the Windows Startup folder after several executions of the virus.

The virus attempts to ping four different IP addresses believed to be located in New Zealand. By pinging these machines, the virus is able to pass the IP address of the infected machine to the virus writer. Port 531 is opened, awaiting connections, allowing remote-control access.

The .B variant will copy itself as C:\Testexe.exe and Winipxa.exe to the Windows directory. This variant also replaces Notepad.exe with an infected version, and backs up the clean version as Notepadx.exe. In addition to the registry changes, the virus also adds an entry to the Win.ini.


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: Eric Chien

Updated: February 13, 2007 11:51:21 AM
Also Known As: Net.666, Explore666
Type: Virus

Repair found infections.
Delete all files created by the virus.
Restore files replaced by the virus with known clean backups.
Remove registry and Win.ini entries.

Writeup By: Eric Chien