The Department of Homeland Security is investigating a 2016 cyberattack on Palm Beach County’s elections office, The Miami Herald reports. Supervisor of Elections Wendy Sartory Link told the Herald she contacted the FBI and DHS after a veteran employee informed her last fall that a ransomware attack hit the office on Sept. 14, 2016, just weeks before the 2016 election. The attack was not made public at the time. Link said she was told the attack targeted Microsoft Word and Excel files, but no one told her the attack had anything to do with voter files. “When I learned about it and I called the state Division of Elections and I called the FBI and my contact at Homeland Security, none of them were aware of it,” Link said. “And, in my conversation with our IT director, he did indicate, to his knowledge, that it hadn’t been reported.”

The employee told Link that other employees were printing out reams of code to try and document the attack. She found the box of documents and sent it along to the FBI, which confirmed that it appeared the files were infected with a ZEPTO virus—which changes file names to “.zepto” until a decryption code is deployed. DHS has since sent a team of six to do a “deep dive” into her department's network, and Link said she would soon report the findings and recommendations. Florida's presidential primary is on March 17. “I wanted this done before March if at all possible,” she told the Herald.