In short
Hang up. Microsoft, Apple, your telecom provider and your bank do not call anyone to report a virus or demand remote access. Anyone who calls and asks you to install a program, enter a number or buy gift cards is a scammer. If you have already installed something or granted access: disconnect the internet, change passwords from another device, call the bank, report it to the police.
How the scam works
The phone rings, someone with a foreign accent or in fluent German introduces themselves as Microsoft, Apple or your telecom provider. Your computer is sending error messages, has been hacked, is spreading viruses. As proof you are told to open the Event Viewer, which shows harmless warnings on every Windows computer. Then you are asked to install a program, AnyDesk or TeamViewer, so the "technician" can help. From then on the caller controls your computer, your online banking and your passwords.
The on-screen variant: a page blocks the browser, blares a siren warning of a virus and shows a phone number. Again: do not call. Close the browser via Task Manager (Ctrl, Shift, Esc), done. The computer was never infected.
How to tell for certain
There is no case in which a genuine provider calls you and demands remote access. None. Everything else is just confirmation.
- The caller supposedly knows your computer has a problem. Nobody can see that from outside.
- It is urgent, and there are threats: blocking, data loss, police.
- You are asked to install something, read out a code or open a website.
- Payment is requested by gift card, transfer abroad or cryptocurrency.
- The displayed number looks German. Numbers can be faked, it proves nothing.
If you have already granted access
No shame, act immediately. Order: first disconnect the internet, Wi-Fi off or cable out, so the access ends. Second, from another device such as your phone, change the passwords for e-mail and online banking. Third, call the bank, have cards and account checked, recall transfers where still possible. Fourth, report it to the police, which can be done online. Fifth, have the computer checked before it goes back online: remove the remote access program, look for further programs, reinstall if in doubt.
Protecting parents and grandparents
The scam targets people who are polite and respect authority. The best protection is a single sentence agreed in advance: "I am hanging up now and calling my technician." Plus: a number next to the phone that may be called before anything is installed. No blame if it happens anyway, or next time they will keep quiet.
Technically it helps to use a user account without administrator rights for everyday use, so nothing can be installed without a password, and to know that the browser can always be closed with Task Manager.