Many antivirus programs flag these service tools as "false positives" because of how they interact with hardware; it is recommended to run them on a dedicated or spare computer if possible.
However, these “hot” downloads from file-sharing sites, torrents, or unknown forums often:
To help you get your printer back in working order, could you tell me: What is your specific printer model (e.g., Pixma G3010)? exact error message or code are you seeing? Have you already tried putting the printer into Service Mode
: Designed to run on Windows OS (specifically Windows XP or later in compatibility mode). How to Use Canon Service Tool v3900
If you attempt to download this software using that specific search term, here is what typically happens: