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01 August 2002
13 February 2007
Systems Affected:

VBS.Sealug@mm is a mass-mailing worm that is written in VBScript. It sends itself to all contacts in the Microsoft Outlook Address Book. The subject of the email is "En Sevdigin" and the attachment is En_Sevdigin.vbs.

The worm also changes the Internet Explorer home page to http:/ /

Antivirus Protection Dates

  • Initial Rapid Release version 02 August 2002
  • Latest Rapid Release version 08 August 2016 revision 023
  • Initial Daily Certified version 02 August 2002
  • Latest Daily Certified version 09 August 2016 revision 001
  • Initial Weekly Certified release date 07 August 2002
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When VBS.Sealug@mm runs, it does the following:

It sends itself to all contacts in the Microsoft Outlook Address Book. The email message will have the following characteristics:

Subject: En Sevdigin
Message:   Hayat yasandigi kadardir. Ötesi ya hatiralarda bir iz, ya da hayallerde bir umuttur. Hüsrani ise bir tek yerde kabul edebilirim: O da yasamaya olanak varken yasayamamis olmaktir.
Attachment: En_Sevdigin.vbs

After the worm sends the email messages, it displays the following two messages:

The worm then copies itself to:
  • C:\En_Sevdigin.vbs
  • %windir%\En_Sevdigin.vbs
  • %system%\En_Sevdigin.vbs

  • %windir% is a variable. The worm locates the Windows main installation folder (by default this is C:\Windows or C:\Winnt) and copies itself to that location.
  • %system% is a variable. The worm locates the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP), and copies itself to that location.

It then searches for these files on all local and mapped drives:
  • Mirc32.exe
  • Mlink32.exe
  • Mirc.ini
  • Script.ini
  • Mirc.hlp

If the worm finds any of these files, it creates the file Script.ini in the same folder as the file that it found. Script.ini contains instructions to send a message that instructs other IRC users to go to http:/ /

Finally, the worm configures the Internet Explorer home page to http:/ / by changing the registry value of Start Page to http:/ / in the registry key HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main.


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.

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

Update the virus definitions, run a full system scan, and delete all files that are detected as VBS.Sealug@mm. Then reset the Internet Explorer home page.

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

To scan for 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 your Symantec antivirus program, and make sure that it is configured to scan all files.
  3. Run a full system scan.
  4. If any files are detected as infected by VBS.Sealug@mm, click Delete.

To reset the Internet Explorer home page:
  1. Start Microsoft Internet Explorer.
  2. Connect to the Internet, and go to the page that will be your home page.
  3. Click Tools, and then click Internet Options.
  4. In the Home page section of the General tab, click Use Current, and then click OK.

Writeup By: Douglas Knowles