Classification

Category :

Malware

Type :

Worm

Aliases :

Coolnow, Menger, JS.Menger, JS/Coolnow

Summary

Coolnow is a worm that uses Microsoft Messenger to propagate. It uses a vulnerability to execute its code via Internet Explorer.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

The worm spreads a message via MSN messenger that contains a link to an infected web page. Some of the messages looks as follows:

 URGENT - Go to http://xxx.xxxxxxxx.xxx/xxxX/mel Now

ATTeNT!oN - Go to: http://xxx.xxxxxxxxx.xxx/xxxxx_Xxx/teztx1.htm Now

Note! There are several links where the worm code is available. We are trying to shut down these pages which are not disabled yet.

When an user clicks on the link in the MSN message, Internet Explorer will open the page and execute the JavaScript code in the page. This is the actual worm.

The worm uses an vulnerability to execute. It goes through the users MSN contact list and sends a message with a link to an infected site to each recipient.

Further information, including a fix for the vulnerability, is available from Microsoft at: https://www.microsoft.com/technet/security/bulletin/MS02-005.asp

For PocketPC users:

This worm does does not affect PocketPC 2002. Internet Explorer version in PocketPC cannot execute the worm code because its JavaScript implementation does not support activation of MSN messenger via a script.