The hack, which was discovered around 5 a.m. Thursday, could affect anyone who has ever done business with the city, Bottoms announced in a briefing later that day.
"We don't know the extent or if anyone's personal data or bank accounts will be compromised," Bottoms told reporters. "All of us are subject to this attack."
Bottoms went on to suggest that residents who have used the city's network to pay fines or bills should keep a close eye on their finances and report any suspicious activity immediately.
Although the 48-year-old mayor said the city's electronic payroll processes would not be affected, she indicated during the briefing that she would be "signing 8,000 checks if necessary."
According to a statement that the city released in addition to the briefing, computers are "currently experiencing outages on various internal and customer facing applications, including some applications that customers use to pay bills or access court-related information."
"At this time, our Atlanta Information Management team is working diligently with support from Microsoft to resolve the issue. We are confident that our team of technology professionals will be able to restore applications soon," it added.
Though officials haven't released details regarding the sum being requested, local news station 11 Alive reported that hackers have demanded $51,000 in bitcoin to unlock the systems. It's unclear if officials will give into the demands.
While city employees have been told to keep their computers turned off until the issue is solved, the local station added that emergency response systems are still fully functional since they're radio-based. The city's public transportation system has also not been affected.
In response to the attack, the Hartsfield-Jackson Atlanta International Airport decided to shut down its free public WiFi and limit some functions of its website as a precaution.
The FBI, US Department of Homeland Security and Secret Service have been called on "for guidance."