Threat Description



Category: Malware
Type: Worm
Platform: JS
Aliases: Coolsite, Cool.A-mm, EML/Coolsites-mm, Coolsites, Coolsite.A@mm


JS/Coolsite.A@mm is a mass mailer written in Java Script. It uses a vulnerability in Internet Explorer to execute itself directly from an infected web page.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.

Technical Details

Further information about this vulnerability, including a fix, is available from Microsoft:

When the worm executes, it first changes the Internet Explorer start page to an adult web site. After that the worm reads emails from the Sent mail folder and sends the following message to each of them:

 Subject:    Hi!!     Body:       Hi. I found cool site! It's relly cool!  

After sending, the worm deletes messages to hide itself from the end user.

The worm is not written to send out any attachments but to activate from a web page. Because of the method that it uses, it might send out with itself attachments which were originally included in the messages in the Sent mail folder.

F-Secure Anti-Virus detect this worm with the current updates.

Description Details: Analysis: Katrin Tocheva and Sami Rautiainen, F-Secure Corp., December 18th, 2001


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