Cash trap detection

A transaction terminal, comprising:

• a media handling device comprising a shutter assembly and a monitor apparatus;
• the shutter assembly comprising a shutter blade;
• the monitor apparatus comprising:
• a processor,
• a time-of-flight (TOF) sensor;
• and
• an ultrasonic sensor;
• wherein the processor configured to use distance measurements provided by the TOF sensor and the ultrasonic sensor to detect when a cash trapping device is present within a media chute behind the shutter blade of the shutter assembly, to detect when the cash trapping device is outside the media chute in front of the shutter blade, to compare the distance measurements provided by the TOF sensor and the ultrasonic sensor against known expected distance measurements between corresponding sensors and a back of an expected shutter blade when the shutter blade is in a closed state, and to cause a security alert to be processed by the media handling device and the transaction terminal.

A method of operating a media handling device for detecting cash trapping attacks, comprising:

• obtaining a first distance measurement from a time-of-flight (TOF) sensor situated in a media chute of the media handling device behind a shutter blade;
• obtaining a second distance measurement from an ultrasonic sensor situated in the media chute behind the shutter blade;
• determining based on the first distance measurement and the second distance measurement whether a cash trapping device is placed within the media chute behind the shutter blade or whether the cash trapping device is placed outside the media chute in front of the shutter blade;
• comparing the first distance measurement and the second distance measurement against known expected distance measurements between corresponding sensors and a back of an expected shutter blade when the shutter blade is in a closed state;
• and
• processing a security operation on the media handling device when the cash trapping device is detected.