Threat description


Category: Malware
Type: Virus
Platform: W32


Ontario is a polymorphic, semi-stealth virus. It stays resident in memory and infectes all executed COM and EXE files. COMMAND.COM is infected by inserting the virus code to an unused part of the file.

Ontario will cause vague printer problems.

Two variants, 512 and 1024 bytes in size, are known.


Automatic action

Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.

More scanning & removal options

More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.


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