Windows
Scam browser pop-ups claiming the computer is infected
Firefox was showing adware-style pop-ups that said the computer was infected and pushed a phone number to call. The technician blocked the sites sending the notifications, and the pop-ups stopped.
Killed once by someone from XL.net, on 2026-04-29.
Affects
Apps
- Mozilla Firefox
What you see
- A browser pop-up says the computer is infected and tells the user to call a phone number.
- Firefox is the browser opening the scam notification.
Why it happens
Suspected Suspected adware or abusive browser notification permissions were generating the pop-ups.
When it shows up
A Windows computer shows scam-style infection pop-ups in Firefox that tell the user to call a number.
You are in this case if:
- Firefox opens or displays a notification claiming the computer is infected.
- The message is a browser pop-up rather than a normal security alert.
1 fix below
The steps that killed it
The steps are behind a quick check
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Someone from XL.net killed this on a Windows computer on 2026-04-29. It is written up from that one repair, so it cites no outside page.