Former Department of Energy (DOE) staffer Charles Harvey Eccleston was sentenced to 18 months in prison for targeting DOE workers with a spearphishing campaign in 2015.

Eccleston, who worked directly for the Nuclear Regulatory Commission (NRC), was also handed a $9,000 fine by U.S. District Judge Randolph D. Moss, which is equal to the sum the FBI provided to Eccleston during the course of the undercover investigation.

Eccleston pleaded guilty in February 2016 to one charge of attempted unauthorized access and intentional damage to a protected computer, according to the U.S. Department of Justice (DOJ).

Eccleston was fired by the NRC in 2010. In 2013 he attempted to sell 5,000 email accounts belonging to people working for an undisclosed U.S. government energy agency to a foreign government, according to the DOJ.