The disclosed embodiments include methods and systems for detecting ATM skimmers based upon radio frequency (RF) signal. In one aspect, the disclosed embodiments include a system for detecting ATM skimmers including a memory storing instructions and one or more processors that execute the instructions to perform one or more operations for detecting ATM skimmers. The operations may include, for example, receiving radio frequency (RF) signal data corresponding to one or more RF signals detected by an antenna located within communication range of the ATM. The operations may also include determining one or more unidentified RF signals of the detected ATM RF signals that differ from one or more baseline RF signals. The operations may also include determining whether the one or more unidentified RF signals are present for a predetermined period of time, and determining whether a skimmer is present at the ATM based on a determination that the one or more unidentified RF signals are present for the predetermined period of time.