Skimming refers to the manipulation of ATMs or payment terminals to allow a fraudster to read the bank card's magnetic strip and the PIN entered by the user. This information is then typically sold to a third party or copied onto a blank card, which is generally used to make purchases or withdraw cash in a foreign country.
How to protect yourself:
Before using an ATM, check for anything unusual that might indicate tampering. Look at the card slot and keypad, for example.
If possible, use an ATM inside a bank. These ATMs are usually accessible even outside of business hours.
If anything seems suspicious, you should refrain from withdrawing money and inform the relevant bank and the police.