Pensacola city authorities became aware of the cyberattack on their municipal computer systems on Saturday morning and many of the systems remained offline on Monday morning, the report said.
The local authorities also alerted the US federal government to the attack as a precaution following the shooting incident, the report added.
All emergency services, including police and medical responses, continued to function in Pensacola, the city authorities said, according to the report.
A Saudi Air Force Aviation student opened fire in a classroom at the base on 6 December, killing three people and injuring seven others before he was shot dead in an exchange of fire.
A few days before the tragic incident, the shooter, identified as Mohammed Saeed al-Shamrani, organised a dinner party to watch mass shooting videos with three other Saudi students other students, a US official said.
The FBI stated that it was investigating the fatal shooting "with the presumption that this was an act of terrorism".