Fake virus warnings: when a notification only pretends to be a virus
"Your PC is infected!" in the corner of the screen is usually not a virus, but a website you once allowed to send notifications. How to recognise it and switch it off in every browser.
Photo: David Pupăză / Unsplash
A warning pops up in the corner of the screen: "Your PC is infected with 5 viruses!" or "Your antivirus subscription has expired". It looks like Windows or a well-known antivirus company. In most cases, it is neither a virus nor a real warning, but a notification from a website.
Where these warnings come from
Many websites ask: "Show notifications?" or "Click Allow to continue". If you click Allow, the website may send you notifications from then on, even when it is not open. Some websites use this to send fake warnings and ads that look like system messages. Your computer is not infected; the website simply has permission to show messages.
How to recognise a fake warning
- It appears in the notification area, often with the name of a browser such as Chrome or Edge and a website address.
- It uses words like "infected", "expired" or "act now" and wants you to click.
- Clicking leads to a website selling antivirus software, or asking for a call or payment.
- Real messages from Windows Security or your antivirus program never show a random website address.
How to switch website notifications off
- Chrome: Settings > Privacy and security > Site settings > Notifications. Remove websites you do not know under "Allowed to send notifications".
- Edge: Settings > Cookies and site permissions > Notifications. Remove unknown websites under "Allow".
- Firefox: Settings > Privacy & Security > Permissions > Notifications > Settings. Remove unknown websites.
- Safari on Mac: Safari > Settings > Websites > Notifications. Set unknown websites to Deny or remove them.
- Chrome on Android: Chrome menu > Settings > Site settings > Notifications.
- iPhone: fake calendar invitations with warnings come from a subscribed calendar. Remove it under Settings > Calendar > Accounts > Subscribed Calendars.
Full-screen warnings with a phone number
Some pages fill the whole screen, play a sound and show a "Microsoft support" number. This is a scam: Microsoft never shows phone numbers in warnings. Close the browser tab; if that does not work, close the browser with the Task Manager (Ctrl + Shift + Esc on Windows) or Force Quit (Cmd + Option + Esc on Mac). Never call the number, never allow remote access and never pay.
If you already called, installed something or paid, change your passwords from another device, inform your bank and contact us. You can also report it to the Federal Office for Cyber Security (BACS).
