Eric Williams, 34, from Nanticoke was pronounced dead at Geisinger CMC in Scranton around 11:30 p.m. Federal officials say an inmate used a homemade weapon to assault the guard.
"This is clearly the darkest day in our institution's short history and we are in shock over this senseless loss of a colleague and friend," said prison Warden David Ebbert.
U.S. Representative Tom Marino released a statement on Williams' death expressing his condolences saying, "Last night's tragedy is a devastating reminder of the dangers our federal prison guards confront every day."
Williams began his career with the Bureau of Prisons in September 11, 2011.
The prison remains in lockdown. The name of the inmate allegedly behind the attack has not been released.