1. When the bank card receives an unknown transfer, you need to check the transfer source first. Judge whether the transfer was made by someone else or a friend you know.

2. Contact the bank: If the transfer source cannot be determined, or the transfer amount is large, you should immediately contact the account opening bank, apply for account inquiry, find out the unknown transfer source, and then request the bank to apply for processing.

3. Handle with caution: If the transfer amount is large and it is suspected of fraud, you should call the police immediately.

4. Protect personal information security: If the bank card is swiped by an illegal POS machine, the card number and password may have been leaked, and the password needs to be reset immediately to prevent further losses.