In an email sent to its employees on Friday, Department of Energy (DOE) revealed that a cyber attack had targeted the department in mid-January; as a result of which the personal details of "several hundred" employees as well as contractors had been compromised.

Confirming the cyber attack in its email, the department said that while personally identifiable information of its employees and contractors was stolen in the hack, no classified information had been compromised.

According to the attack-related details shared by the DOE, the January cyber attack allowed the hackers to penetrate the computers and servers at the Washington headquarters of the department and pilfer personal data of staff and contractors.

The DOE also revealed in the email that it is, together with federal law enforcement authorities, investigating the attack; and added that once it has identified the individual affected employees, it will notify them and guide them about measures they can follow to ensure that they remain protected against any similar cyber attacks in the future.

About the investigation initiated into the attack, the DOE said in the email: "The Department's Cybersecurity Team, the Office of Health, Safety and Security and the Inspector General's office are working with federal law enforcement to promptly gather detailed information on the nature and scope of the incident and assess the potential impacts to DOE staff and contractors."