What caused the internet outage at University of Michigan this week?
ANN ARBOR, Mich. (CBS DETROIT) - The University of Michigan announced Wednesday morning that its internet connectivity and Wi-Fi network had been restored after a prolonged outage.
University President Santa J. Ono announced that an investigation into what the school called a "security issue" is ongoing.
The outage paralyzed all three U-M campuses right as the fall semester began.
"People would be outside of the quads with their phones trying to get service," said student Milia Mladjan. "But everyone was trying to get service, so service was also really slow."
"My parents were trying to reach me, and I had no service. I couldn't reach them," said student Maddy Scarth. "So, they were trying to call the school, and of course, the school couldn't call anyone else, so all around, it was definitely really stressful."
"It was pretty stressful because I have no idea how to get anywhere, and I couldn't use Google Maps or anything," said student Jordan Schneider.
Cybersecurity experts said the incident is the hallmark of a breach.
"The fact that they took their systems down, like proactively took their systems down, is the indication that it is a cybersecurity incident," said co-founder and CTO of SensCy Dave Kelly. "The reason why you do that is that you don't want it to spread further."
"They probably didn't know to what extent they'd been compromised," senior penetration tester and ethical hacker at NetWorks Group Chris Neuwirth said. "They probably didn't know how many accounts were compromised or the initial entry point that the threat actor used to gain access into the network."
Sources close to the investigation told CBS News Detroit that U-M detected malware on its Wi-Fi network and decided to shut it down in response.
So, did the school avoid a disaster? Neuwirth thinks it very well could have.
"They likely had very robust backups and data recover, plans, procedures in place that helped them make the decision very confidently and rapidly," he said. "Four days in that they're already bringing up their systems tells me that it's likely that a lot of what they had been preparing for worked."
Kelly said these types of incidents are on the rise.
"There's been a large increase in cybersecurity incidents," he said. It's been trending up, quite frankly, for the last several years. It used to be that these threat actors were targeting the government and Fortune 500 companies, but they've started to, more and more over the years, look at universities."
University officials said they cannot share any information while the investigation is ongoing.