A Geico data breach that lasted over a month earlier this year exposed customers’ driver’s license numbers to hackers, according to a notice filed with California’s attorney general earlier this month.

The filing, first obtained and reported by online newspaper TechCrunch on Monday, included a message sent to an unspecified number of Geico customers, stating that “between January 21, 2021 and March 1, 2021, fraudsters used information about you — which they acquired elsewhere — to obtain unauthorized access to your driver’s license number through the online sales system on our website.”

“We have reason to believe that this information could be used to fraudulently apply for unemployment benefits in your name,” added Geico, the second-largest auto insurer in the country.