Worm:W32/Kelihos

Classification

Category :

Malware

Type :

Worm

Aliases :

Worm:W32/Kelihos, Worm:W32/Kelihos.A, Backdoor:Win32/Kelihos.A, Email-Worm.Win32.Hlux, Trojan.ADH.2

Summary

Worm:W32/Kelihos uses the infected system to send out spam email messages; it also connects to a remote server, from which it may receive additional instructions.

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

Worm:W32/Kelihos spreads in spam email messages that contain a link to the worm's executable file, which may be hosted on a malicious or compromised website. On clicking the link in the message, the worm is installed on the system.

On execution, the worm modifies the Registry so that it is started each time the system is booted. It then sends out spam email messages using its own built-in SMTP engine

Kelihos also contacts a remote server for additional instructions and/or additional updates to itself. Communication between server and worm may be encrypted and rerouted through rapidly changing domains (fast-flux) in order to evade detection by security programs.