By Audrina Bigos

CHICAGO (CBS) — The ATM inside a Target that is one of the busiest stores in Chicago’s loop was surrounded by police after someone found a skimmer inside the machine.

Police pulled the device from the TCF bank ATM inside the Target at State and Madison Sunday night.

The skimmer, a small device used to steal credit card information while from those using a card at the ATM, was found by someone doing maintenance.

Anyone who has used that machine should check accounts for fraudulent activity and notify their bank immediately of anything suspicious.

According to TCF’s website, the bank provides zero fraud liability, meaning account holders are not responsible for fraudulent charges made as long as they contact the bank within 60 days.

Even in such a busy store, someone managed to put the skimmer on the ATM without being noticed.

No one is in custody, but police are investigating.