Sean Caffery admitted to accessing accounts and stealing usernames, email addresses and the military rank of more than 800 users.
Sean Caffery admitted to accessing accounts and stealing usernames, email addresses and the military rank of more than 800 users.

A U.K. citizen has pleaded guilty on June 15 to hacking into a U.S. Department of Defense (DoD) communications system three years ago and accessing the PII on 800 people and 30,000 individual satellite telephones.

Sean Caffery admitted to accessing accounts and stealing usernames, email addresses and the military rank of more than 800 users, according to a UK National Crime Agency (NCA) press release. The NCA stated that Caffery was arrested in March 2015 after an intelligence agency discovered the DoD hack originated from his internet connection and a follow up forensic examination of his computers found the stolen data.

The hack took place on June 15, 2014 and the DoD estimated it costs about $628,000 to fix the damage caused by Cafferty's attack.

Janey Young, investigations manager at the NCA, said “After strong partnership working between the NCA, the FBI and the DoD's Defense Criminal Investigative Service there was very clear, very compelling evidence against Sean Caffrey.

A sentencing date has not been set.