Opened a suspicious file? Do this now

Disconnect the device from Wi-Fi and mobile data. Do not type any passwords on it.

From a different, clean device, change the password of your email first, then banking, social media and Telegram. Turn on Two-Step Verification and end all other sessions (Telegram → Settings → Devices).

Run a full antivirus scan. If you are not sure the device is clean, back up your photos and documents and reinstall the system.

If you use banking apps, call your bank using the number on your card. Warn your contacts that messages from your account may not be from you. Report the sender to Telegram.