The US branch of the Israeli arms manufacturer Elbit Systems has confirmed that it was hacked in early June, according to America's TechCrunch newspaper.
The Texas-based company said the breach occurred on 8 June and that 369 people were affected.
An alert sent out to impacted customers by a law firm on behalf of Elbit said it discovered the breach after noticing unusual activity on its network, which was immediately shut down to secure the environment.
The personal information of employees that was stolen included employee names, addresses, dates of birth, direct deposit information, ethnicity and Social Security numbers.
Impacted individuals were notified in July and offered 12 months of free identity protection and credit monitoring services, the company said.
Elbit Systems of America did not attribute the breach to a particular threat group or government or say for what reason it believes it was targeted
However, Elbit Systems is often the target of campaigns by human rights groups and anonymous hackers. The Israeli firm produces surveillance technology for the illegal Separation Wall in the occupied West Bank and is said to manufacture the engines for 85 per cent of the country's military drones, among other weapons components.
The Israeli arms manufacturer is said to also have supplied drones used in the war on Gaza in 2014, when over 2,200 Palestinians – 500 of them children – were killed in only 51 days.