Threat Description

Riskware: ​W32/mIRC


Category: Riskware
Type: Riskware
Platform: W32
Aliases: Client-irc.win32.mirc


Useful, legitimate software which could possibly be misused for malicious purposes.


Automatic action

Once detected, the F-Secure security product will automatically block the suspect file from running and prompt the user to select a further desired action.

Excluding a file from scanning

If you are aware of and accept any potential risk associated with this program, you can configure the F-Secure security product to exclude it from scanning.

Suspect a False Alarm?

If you suspect a file has been incorrectly identified as malicious, (that is, it is a False Alarm or a False Positive), please first ensure your F-Secure security program is up-to-date with the latest detection database updates, then rescan the suspect file.

If you continue to suspect a False Alarm, you may submit a sample of the suspect file to our Security Labs for further analysis via the Sample Analysis System (SAS).

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

Riskware:W32/mIRC is an Internet Relay Chat (IRC) client that can be silently subverted by malware to become a backdoor. By itself, the program is not malicious.


Malware such asBackdoor:W32/Zapchast and its variants can use malicious configuration files to turn the mIRC-client into a backdoor. The malicious configuration files are detected as Backdoor.IRC.Zapchast.

In addition to subverting the mIRC client, these files will also contain the name of an IRC channel which the mIRC-client will automatically try to join on each startup.

Sometimes, Zapchast variants will use additional batch files which provide added functionality, such as performing registry changes to create a launchpoint for the backdoor. These auxiliary batch files are detected as Trojan.BAT.Zapchast.

Description Created: 2009-08-25 05:21:32.0

Description Last Modified: 2010-03-26 08:35:47.0


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