Threat Descriptons



Category :


Type :


Aliases :

Email-Worm:W32/Zhelatin.KC, Email-Worm:W32/Zhelatin.KC


Zhelatin.KC is a bot that communicates via Overnet P2P protocol and is mainly used to send spam. It has rootkit functionalities that hide its presence in the infected system.


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

Zhelatin.KC does the following upon initial installation:

  • Disable Windows File Protection
  • Creates a copy called %WindowsDirectory%\spooldr.exe
  • Drop its rootkit component %SystemDirectory%\spooldr.sys
  • Infects %SystemDirectory%\dllcache\tcpip.sys
  • Exits current process

The other routines of the malware are continued after the infected system is rebooted.The following is how the malware is launched during system startups:

  • The infected tcpip.sys gets loaded by the OS
  • The infected tcpip.sys loads spooldr.sys
  • Spooldr.sys injects spooldr.exe to the explorer.exe process

Once loaded, spooldr.exe creates a file called spooldr.cfg which contains its initial list of peers in the current directory of the running process. Since it does not have its own process, it will take the current directory of explorer.exe instead. This usually leads to spooldr.cfg being created in the home directory of the current user. Additionally, Spooldr.sys hides all filenames that start with "spooldr" in the system, therefore you might not find the created files once the rootkit has been loaded.The malware then tries to communicate with the other peers via the Overnet P2P protocol on how to proceed.The malware has the ability to do the following:

  • Harvest email addresses but avoid those that contain certain strings
  • Download messages to be use in spam
  • Send spam emails
More Support


Ask questions in our Community .

User Guides

Check the user guide for instructions.

Contact Support

Chat with or call an expert.

Submit a Sample

Submit a file or URL for analysis.