Hy-Vee is telling shoppers to check their bank accounts after detecting a data breach at some of its cash registers.

The company says it is focusing on card sales fuel pumps, drive-thru coffee shops and restaurants, including Market Grille, Market Grille Express and the Wahlburgers.

There are no details about when the breach happened or what locations were impacted. The press release said the investigation is in its early stages so that information will be released later.

Hy-Vee contacted cyber security firms after noticing unauthorized activity on their payment processing systems, according to a press release. Hy-Vee also reached out to federal law enforcement and the credit card companies.

How to keep your data safe

Here’s the bad news. Gas & Electric Credit Union president Daryl Empen said there’s not that much you can do to keep yourself from becoming a victim.

“There’s no system that’s 100% secure,” he said. “There’s not a lot you can do if a merchant’s been hacked.”

What you can do is be careful about swiping your card instead of using the chip.

“A lot of the fraud was based on that magnetic stripe and cards were easier to be counterfeited using the magnetic stripe,” Empen said.

But not all registers have the chip readers and they don’t always work.

“As long as you swipe the card there’s more chance that that card could be counterfeited.” Empen said.

You can also set up alerts for unusual spending so you know something is wrong as soon as possible.

“Most fraud occurs within the first 24 hours,” Empen said. “They know that they’re going to get caught sooner or later or that there is a daily limit.”

Empen said if you are really worried, just go the old-fashioned route.

“The only fool-proof way to prevent card theft would be to go to cash only,” he said.