The ransomware attack on the city of Atlanta, which marked its one-year anniversary last week, remains the most extensive breach on a local government to date.

A number of services in the major metropolitan center and home to the nation's busiest airport were hamstrung, keeping some city systems, including city payment and court information portals, offline for nearly a week after the attack was discovered.

Last November, a federal grand jury in Newark, New Jersey, returned a six-count indictment charging two Iranian nationals with creation of the SamSam ransomware that targeted not only the Atlanta government but other municipalities, hospitals and companies around the United States.