The files posted "appear to come largely from a single shared network drive" used by the Parks and Recreation Department, St. Paul Mayor Melvin Carter said on Monday evening.

Bill payment information, like credit card numbers, is generally handled by “cloud-based” applications and should not have been affected by the hack, the mayor said.

The mayor of Saint Paul, Minnesota's capital city, has confirmed that the Interlock ransomware gang is responsible for a cyberattack that disrupted many of the city's systems and services in July.