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Discovered: June 28, 2002
Updated: February 13, 2007 11:39:24 AM
Type: Trojan Horse
Systems Affected: Windows

Swporta.Trojan is a Trojan that attempts to modify the Web browser's home page.

NOTE : Virus definitions dated prior to June 28, 2002 may detect this threat as Backdoor.Trojan.

Antivirus Protection Dates

  • Initial Rapid Release version June 28, 2002
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version June 28, 2002
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date July 03, 2002

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

Writeup By: Yana Liu

Discovered: June 28, 2002
Updated: February 13, 2007 11:39:24 AM
Type: Trojan Horse
Systems Affected: Windows

This Trojan requires various components in order to work. The components may have the following file names, depend on the version of the Trojan,

  • Winn32.exe
  • Winn32.mcs
  • SWportal*.exe
  • SWCaller*.exe
  • SWportal.js
  • SWportal1.gif
  • SWportalero.html
  • SWportalkop.gif
  • SWportallink.html

When the Trojan is executed, it does the following,

It changes these values

Start Page

in the registry key

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\

to a HTML page on the local hard drive, for example, C:\<the folder name of the Trojan program>\Winn32.html

In this way, the Trojan modifies the default Internet Explorer home page to the website predefined by the hacker.

It then adds the subkey


under the registry key


and sets its value to

SWStartPage Yes

The Trojan may also add a value that refers to itself to the registry key


so that the Trojan runs each time when you start Windows.

Some text files may be created by the Trojan. These files are named in the form of www.<some URL>.cxq. Most of the URLs relate to some adult Internet site in the Netherlands.


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: Yana Liu

Discovered: June 28, 2002
Updated: February 13, 2007 11:39:24 AM
Type: Trojan Horse
Systems Affected: Windows

Update the virus definitions, run a full system scan, and delete all files that are detected as Swporta.Trojan.

  1. Delete the value that refers to the Trojan program from the registry key

  2. Delete the registry key

  3. Remove the value data from

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Start Page
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Startpagina

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

To scan with Norton AntiVirus and delete the infected files:
  1. Obtain the most recent virus definitions. There are two ways to do this:
    • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and 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 have undergone full quality assurance testing by Symantec Security Response. They 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.
  2. Start Norton AntiVirus (NAV), and make sure that it is configured to scan all files.
  3. Run a full system scan.
  4. Write down the names of all files that NAV detects as Swporta.Trojan and then delete them.

To remove 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

  4. In the right pane, delet the value that refers to any of the files that were detected as Swporta.Trojan
  5. Delete the registry key

  6. Navigate to the key

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
  7. In the right pane, if they exist, double-click each of these values

    Start Page
  8. For each one, clear the text in the Value Data box and then click OK.
  9. Click Registry, and click Exit.

Writeup By: Yana Liu