An eagle-eyed Chevron employee in Hayward thwarted two would-be thieves in their efforts to steal credit card information from unwitting customers right before Christmas.

The employee spotted suspicious-looking men near an ATM, and sensing something was off, called the police, as KRON reports. When he approached the machine, he discovered a skimmer attached to the card reader.

But that wasn't all; upon arrival, an Officer Dadej discovered that one of the thieves had also installed a camera in a side panel of the ATM. The point of the false panel is purportedly to capture pin numbers as they're inputted on the keypad.

"Thank goodness the alert employee realized something wasn't right and called Hayward PD immediately," a Hayward Police Department Facebook post about the finding reads. "Officer Dadej went to the 7/11 store across the street and discovered a similar device was installed on their ATM as well!"

Fortunately, Chevron's in-store cameras were working, and did capture an image of the suspects. Police are asking anyone who recognizes the men to call the Hayward police.

Hayward police spokesperson Sargeant Ruben Pola tells SFGATE that such a crime is "very uncommon" in Hayward, adding, "It's been quite some time since we could locate a skimmer."

The technology behind credit card skimming has become more sophisticated in recent months, as a September report by CNBC outlined. Authorities estimate that thieves are making away with around $2 billion in fraudulent charges around the world, thanks to new ways to create theft devices mostly undetectable to the average person. Police recommend that ATM users look for cues that a machine looks off before using and to always cover the keypad when entering a pin number.

Alyssa Pereira is an SFGATE staff writer. Email her at apereira@sfchronicle.com or find her on Twitter at @alyspereira.