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Discovered: April 19, 2001
Updated: February 13, 2007 11:56:45 AM
Type: Worm

JS.Congrats.A@mm is a JScript email worm. It arrives as an attachment named Original.js which may be displayed as Original.jpg. When executed, the worm emails itself to everyone in the contact list of your Microsoft Outlook address book.

Antivirus Protection Dates

  • Initial Rapid Release version April 19, 2001
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version April 19, 2001
  • 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: Serghei Sevcenco

Discovered: April 19, 2001
Updated: February 13, 2007 11:56:45 AM
Type: Worm

When run, JS.Congrats.A@mm recursively deletes all .jpg files found on the drive C, with the exception of those in the root directory. It then sends itself to everyone in the contact list of your Microsoft Outlook address book. The email message is as follows:

Subject : congrats ...ÿ

I am not sorry, but you have been befooled.
Some files in your system have been deleted.
Believe it or not.... you have infected your computer
(This is followed by additional text).

Attachment: Original.js

    NOTE: The attachment has the MAPI property for the display name (PR_DISPLAY_NAME) set to Original.jpg. This can cause your email program to display the attachment as Original.jpg file. For example, Microsoft Outlook will display the attachment as Original.jpg, although its icon will still be the icon for a JScript (.js) file.
The message body is imported through the dropped file C:\Windows\Start Menu\Programs\StartUp\Original.txt. The attachment is imported through the dropped file C:/Original.js.

Finally, JS.Congrats.A@mm delivers confirmation of its execution to rs_sandhu@123india.com. If the C:\CuteFTP\Smdata.dat file exists on a local computer, the worm attaches this file to the confirmation message that it sends. The Smdata.dat file may contain confidential information, such as a list of FTP-server login information.


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: Serghei Sevcenco

Discovered: April 19, 2001
Updated: February 13, 2007 11:56:45 AM
Type: Worm

To remove this worm:

  1. Run LiveUpdate to make sure that you have the most recent virus definitions.
  2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
  3. If any files are detected as infected by JS.Congrats.A@mm, click Delete.
  4. Using Windows Explorer, locate and delete the following files:
    • C:\Windows\Start Menu\Programs\StartUp\Original.txt
    • C:\Original.js

Writeup By: Serghei Sevcenco