A cyberattack on Cellcom, a regional telecommunications provider based in Wisconsin, has disrupted phone and text services for thousands of customers across Wisconsin and Michigan’s Upper Peninsula since May 14. The company confirmed the incident on May 20, attributing the outage to a targeted cyberattack that affected its voice and SMS systems.
In a letter and accompanying video message, Cellcom CEO Brighid Riordan stated that the attack was confined to a specific segment of the network, separate from where sensitive customer data is stored. “We have no evidence that personal information related to you, your name, your addresses, your financial information, is impacted by this event,” Riordan assured customers.
Upon detecting the breach, Cellcom activated its incident response protocols, which included engaging external cybersecurity experts, notifying the FBI and Wisconsin state authorities, and initiating a comprehensive recovery strategy.
As of May 22, some services have been partially restored. Cellcom users reported the ability to make calls to other networks, although receiving calls from non-Cellcom numbers remains inconsistent. The company anticipates full service restoration by the end of the week but has not provided a specific timeline.
The outage has significantly impacted customers, including small business owners like Andy Tobias, whose window cleaning business suffered due to communication disruptions.
Cybersecurity experts emphasize that such incidents highlight the vulnerability of critical infrastructure. Dr. Tyler Baeten, an IT instructor at Fox Valley Technical College, noted, “This isn’t a Cellcom issue; this is part of the growing trend nationwide, where we’re seeing our infrastructure being targeted.”
To safeguard personal information, experts recommend using end-to-end encrypted communication platforms and freezing credit with major bureaus—Experian, Equifax, and TransUnion—to prevent identity theft.
Cellcom has pledged to compensate customers for the downtime, though specific details have not been disclosed. The company continues to work diligently to restore full services and has committed to transparent communication throughout the recovery process.
