Many of Chipotle's Point-of-Sale (POS) devices had malware on them between March 24, 2017 and April 18, 2017. The malware searched for track data (which sometimes has cardholder name in addition to card number, expiration date, and internal verification code) read from the magnetic stripe of a payment card as it was being routed through the POS device.

You can read more about it here and also check to see if the Chipotle(s) you visited were affected:

Chipolte.com - Chipotle Mexican Grill Reports Findings from Investigation of Payment Card Security Incident