DDS Safe, an online cloud-based data backup system that hundreds of dental practice offices across the United States are using to safeguard medical records and other information of their patients from ransomware attacks has been hit with ransomware.

Provided by two Wisconsin-based companies, Digital Dental Record and PerCSoft, the backend system of affected medical records retention and backup solutions has probably been hit by Sodinokibi ransomware, also known as Sodin or REvil malware.

Though it’s not yet clear how attackers managed to compromise the company’s infrastructure, the latest ransomware attack is yet another example of successful supply chain attack, crippling computer systems in 400 dental practice offices around the United States this week.