A Reddit user, who goes by atlas5280 on the site, claimed to narrowly avoid becoming a victim of credit card theft after discovering a false cover on the card slot of an ATM that contained a small electronic device known as a "skimmer."

Skimmers read and store credit and debit card information, but can be difficult to detect if the ATM user isn't careful.

The user posted a photo of the fake cover and skimmer on Reddit, thanking the online community for warning about the ATM scam.

Reddit - reddit.com

When most people think about credit card theft, their minds turn to online shopping on an insecure website, or physically losing a card that winds up in the wrong hands. The fact of the matter is, scammers have evolved their techniques, and skimmers represents one of the lesser known forms of credit card theft, Consumerist reported.

The good news is that, once you're aware of the issue, there are tricks you can use to determine whether a given ATM has a skimmer. The simplest way to do this is to give the card slot a gentle wiggle and see if it pops off. Authentic card slots are fixed onto the machine, so if its removable, chances are it contains a skimmer.

Skimmers tend to be placed strategically during certain times of the week.

The best way to properly protect yourself is to think like a scammer. Since getting caught planting an electronic card reader on an ATM carries serious criminal penalties, scammers are more likely to install them on outdoor machines, away from highly trafficked areas. "The chances of getting hit by a skimmer are higher on the weekend than during the week, since it's harder for customers to report the suspicious ATMs to the bank," according to PC Magazine's Max Eddy. 

"Criminals typically install skimmers on Saturdays or Sundays, and then remove them before the banks reopen on Monday," Eddy added.

vverve - bigstockphoto.com

If you do discover a skimmer, contact your bank — especially, if you discovered it after sliding your card. More banks have installed cameras on ATMs, so there's a chance that the scammer could be identified by law enforcement if someone reported the scam. At the very least, it'll ensure that any fraudulent charges are contested so you can get your money back.