The city of Chicago on Friday said that employee emails were compromised in a Jones Day data breach involving Accellion’s FTA file sharing service.
The cyber-attack started in December 2020, when a critical vulnerability was identified in the 20-year-old large file transfer service that reached end-of-life on April 30, 2021.
Roughly 50 customers were still using FTA when the security incident took place, but only some of them experienced significant data loss, Accellion claimed.
In February 2021, the major U.S.-based law firm Jones Day confirmed that it was impacted by the attack, after the cyber-criminals behind the Clop ransomware published on their Tor-based leaks website documents allegedly stolen from the company.
On Friday, the city of Chicago revealed that some employee emails that were given to Jones Day “as part of an independent inquiry being conducted by the firm” were compromised in the incident.
The data breach only affected the Accellion FTA service and involved “emails sent or received from four former City employees over a two-year time period,” the city said.
The Chicago Department of Assets, Information and Services (AIS), the city also reveals, has already notified the FBI and the Illinois Attorney General’s office on the leak and took the necessary action to ensure that the emails were removed from the file transfer service.
“While the city is not aware of any fraud that might have resulted from this event, it has taken the matter very seriously and responded accordingly,” the city says.
Furthermore, the city says it was able to determine the number of impacted people and that it has already taken steps to notify the individuals who might have had personal information included in the compromised email files, either directly or through a notice on its website and a state-wide media alert.