Wisconsin wi-fi supplier Cellcom has confirmed {that a} cyberattack is answerable for the widespread service outage and disruptions that started on the night of Might 14, 2025.
The incident disrupted voice and SMS providers for purchasers throughout Wisconsin and Higher Michigan, leaving subscribers unable to make telephone calls or ship textual content messages.
At the moment, after days of simply calling it a technical outage, Cellcom CEO Brighid Riordan has confirmed what was already suspected: that the corporate suffered a cyberattack.
“We skilled a cyber incident. Whereas that is unlucky, it isn’t one thing we had been unprepared for,” reads a letter from Cellcom CEO Brighid Riordan.
“We have now protocols and plans in place for precisely this sort of scenario. From the beginning, we have adopted these plans — together with partaking exterior cybersecurity consultants, notifying the FBI and Wisconsin officers, and dealing across the clock to deliver programs safely again on-line.”
“The incident was focused on an space of our community separate from the place we retailer delicate data associated to you, our Cellcom/ Nsight household. We have now no proof that non-public data associated to you, your identify, your addresses, your monetary data, is impacted by this occasion.”
Cellcom initially claimed the disruption was brought on by a technical situation, stating that knowledge providers, iMessage, RCS messaging, and 911 emergency providers remained operational.
Nonetheless, customers grew to become more and more annoyed with the lack of service and the shortcoming to port their numbers to different carriers as a result of Cellcom’s platforms having points.
On Might 19, Cellcom started bringing a few of its providers again on-line, together with SMS textual content messaging and making and receiving telephone calls to different Cellcom subscribers.
Nonetheless, the corporate says that whereas they cannot promise when providers might be restored, they’re making an attempt to revive full service by the tip of the week.
“Whereas we want to present a timeline for full restoration, we’re unable to share precise milestones with full confidence. Our group continues to construct on the progress shared yesterday and our greatest estimate is that full service might be restored by or earlier than the tip of this week,” reads a service updates web page on Cellcom’s website.
For Cellcom subscribers having points recovering providers, it’s endorsed that they allow airplane mode for 10 seconds after which disable it once more. If that doesn’t work, subscribers ought to energy down their telephones and begin them up once more to aim to provoke providers.
Yesterday, BleepingComputer contacted Cellcom with questions concerning the disruption brought on by a ransomware assault or one other cyber incident, however didn’t obtain replies to our questions.
Cellcom CEO Brighid Riordan additionally shared a video for subscribers to elucidate the scenario and what they’re doing to get well from providers.
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