August visitors to Tettegouche State Park in northeastern Minnesota may have had their credit card information compromised due to a malicious software attack on park computers.

The state Department of Natural Resources has urged people who visited the park from Aug. 22 to 25 to review their credit card statements for any suspicious activity.

While officials are warning visitors about the breach, they have not found any evidence that credit card information was misused. According to the department, the park had 400 credit card transactions during the period in question.

No other DNR or state technology systems were affected, authorities said. “The virus was isolated to computers at the park,” the DNR said in a news release.

DNR officials learned of the virus on Aug. 25, when an internet technology expert discovered a spike in activity on park computers. The expert then isolated the site, protecting park data and replacing the infected equipment.

Park officials also notified visitors to be cautious of e-mails asking for personal information that claim to be from the DNR.

This year, Minnesota has experienced several hacking incidents, including a breach in state databases by someone claiming to be seeking justice for Philando Castile, who was shot last year by a St. Anthony police officer. In February, the personal data of 2,800 Bloomington public school employees was stolen via cyberscam.