City of Franklin investigating data breach that possibly exposed personal info, no evidence at this time it's been misused

FRANKLIN, Wis. (CBS 58) -- The City of Franklin is investigating a data breach that happened nearly a year ago and could impact an untold number of residents.

So far, the city is unaware of any personal information being misused, but they also do not know who is responsible.

Names and important tax information may have been hacked when a third party accessed a Franklin server last August.

Notification letters were only recently sent out, but city leaders say they're doing everything they can to beef up security.

It was August of 2024 when an unauthorized third party infiltrated the City of Franklin's network, accessing a server that had information potentially going back to the 1960s. At the time, the city was unaware personal information had been exposed.

But when a forensic and data review finished this May, they realized certain data files may have been accessed.

Right now, there is no evidence the information has been misused. But per state and federal law, a notification letter was sent to every person potentially compromised.

It said names, dates of birth, social security numbers, even tax ID numbers may have been hacked.

But the letter was unsigned. It also encouraged people to log onto a credit monitoring website and call an out-of-town phone number. Many people thought it was a scam.

At Tuesday's common council meeting, resident Linda Mathwig said, "It appears to many of us this could be fraudulent."

Mathwig added, "My fear is citizens of Franklin may call the phone number or access the website and potentially be taken advantage of."

On social media, Franklin Mayor John Nelson confirmed, "The letter you received DID come from the City of Franklin."

At Tuesday's meeting, he addressed the hack and the letter, saying, "Should it have been signed? 100% that letter should have been signed. Absolutely."

Nelson told the audience that attempted data breaches happen frequently. "And when it happens," he said, "we report it to the police, police start investigations."

No one knows who is responsible for this one yet, but the FBI is investigating.

Franklin is increasing its cyber security with the help of IT specialists.

But some people are wondering why it took so long for the city to discover the data had been exposed, and then to notify people about it.

Mathwig asked, "Why has it taken nearly 11 months to notify the residents of Franklin?"

The city said it took time to investigate the full scope of the breach, then to prepare notification letters, search for addresses, and get a vendor to send the letters out.

Nelson said, "We want to make sure we're giving out clear and concise information, not to cause a lot of fear, uncertainty."

The city encourages anyone impacted to monitor their credit report.

Franklin is also providing free access to a credit monitoring service for one year.

The city will explain the breach further at Franklin's August 5 common council meeting.