Account protection

First make sure your devices aren't infected with malware. Then log in to your Yandex ID and complete the following:

1. In the Email addresses and phone numbers section, delete all other numbers or emails and link your phone number to your account.
2. In the Login history and devices section, disable all other devices, delete programs you don't recognize and press the This isn't me button next to all actions that weren't you.
3. In the Passwords and login section, change your password and enable two-factor authentication.

Check out Yandex ID Help for more about security and strong passwords.