A data breach reveals the personal information of 237,000 US government workers.

Sources told Reuters on Friday that a huge data breach at the US Transportation Department (USDOT) put the personal information of about 237,000 current and former federal workers at risk.

Sources said that the hacking was aimed at the systems that handle government workers’ TRANServe transit perks, which pay for some of their commuting costs.

There were no stories right away about personal information getting out or being used for bad things.

In an email seen by Reuters on Friday, the USDOT told Congress that its first look into the data breach has “isolated the breach to certain systems at the department used for administrative functions, such as processing employee transit benefits.”

In a statement to Reuters, the USDOT said that the breach did not affect any safety systems. It didn’t say who could have done the hacking.

The breach is being looked into by the department, which has blocked access to the transit benefit system until it is fixed and safe again.

For federal workers who use public transportation to get to work, the highest benefit is $280 per month. There were 114,000 current employees and 123,000 past employees who were affected by the breach.

Hackers have gone after government workers and departments in the past.

In 2014 and 2015, sensitive information about more than 22 million people was stolen from the U.S. Office of Personnel Management (OPM). This included the fingerprint data of 5.6 million people, 4.2 million of whom were government employees, and 4.2 million of whom were not.

Russian hackers who used SolarWinds and Microsoft software to get into U.S. government agencies broke into private Justice Department networks and read emails at the Treasury, Commerce, and Homeland Security departments. In 2021, Reuters said that nine government agencies were broken into.