W32.Oporto.3078 Virus

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Discovered: October 07, 1999
Updated: February 13, 2007 11:53:28 AM
Type: Virus

W32.Oporto.3078 is a virus that infects Windows PE executables. It is a direct infector of EXE files. It works under Windows 95, 98 and NT.

Antivirus Protection Dates

  • Initial Rapid Release version December 21, 2000
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version December 21, 2000
  • Latest Daily Certified version September 28, 2010 revision 036

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

Writeup By: Wason Han

Discovered: October 07, 1999
Updated: February 13, 2007 11:53:28 AM
Type: Virus

If an infected file is executed on Sep. 24, the virus creates an endless number of message boxes that contain the following text:

During infection, the virus overwrites the first six bytes at the entry point of the host program to transfer control to the viral code upon execution of the file. These six bytes are stored in the virus body and restored in memory when the viral code is executed. After decrypting its viral code, the virus searches for 30 Windows API functions used for finding and infecting files. Then, it allocates memory, copies itself to that newly allocated memory and executes from there. It does not infect files that start with NTVD. If it finds a file named ANTI-VIR.DAT, it deletes this file.


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: Wason Han

Discovered: October 07, 1999
Updated: February 13, 2007 11:53:28 AM
Type: Virus

To remove this virus, scan files with Norton AntiVirus and repair any infected files.

Norton AntiVirus users can protect themselves from this virus by downloading the current virus definitions either through LiveUpdate or from the following webpage:


Writeup By: Wason Han