Classification

Category :

Malware

Type :

-

Aliases :

IIS worm, Internet Information Server worm, IIS

Summary

ISS Worm (generic description).

An IIS worm is a code that scans for and infects webservers running Microsoft IIS (Internet Information Server) software. This code is usually an HTTP request that exploits a vulnerability in IIS software and makes a server run binary code that follows the request. Some IIS worms do not exist in a file form. They only exist as a memory process. Disinfection of such worms is quite easy - special patches need to be installed to IIS software and a server has to be rebooted.

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

An IIS worm can make a few changes to a system to allow a hacker to get unauthorised access to it. For example CodeRed worm copied command interpreter to the scripts folder of an IIS server and a hacker can run that file from remote computer to get full access to an infected webserver.

Some IIS worms change startup pages of IIS servers they infect.

Most famous IIS worms: CodeRed, CodeBlue, CodeYellow.