LEWISTON — Central Maine Healthcare has shut down its network servers and phone systems after identifying “unusual activity” within its computer system.

A statement released by the hospital group said technicians monitoring the CMHC system Sunday shut off all information technology applications and hardware, including network servers and phone systems, after spotting the activity.

The statement said Central Maine Medical Center in Lewiston, Bridgton Hospital and Rumford Hospital are receiving and treating patients, and all physician offices and outpatient sites remain open. The hospitals and physician offices will be informing patients if elective procedures and office visits will be rescheduled, the statement said.

Patients have reported not being able to get into the patient portal, connect with offices over the phone or have had non-emergent appointments canceled.

Calls to a Central Maine Healthcare spokesperson were not returned before the Sun Journal’s print deadline Monday evening.

The outage, if proven to be a cyberattack, would be the second impacting Maine hospitals in just over a week.

A week ago, officials at Covenant Health, which owns St. Mary’s Health System, disconnected from all of its hospitals’ data systems due to a “cyber incident” that a hospital spokesperson confirmed was initiated by an outside group.

Jennifer Sullivan, spokesperson for Covenant Health, said Monday that the hospital group, which also operates St. Joseph Hospital in Bangor, St. Andre Health Care in Biddeford and Community Clinical Services, is still working to restore full access to its systems.

“Recovery efforts are underway as we continue our investigation into the scope of the cybersecurity incident,” she said. “We have engaged best-in-class outside parties to assist us in determining the details of what happened and to restore full system access as soon as possible.”

She said they are working to provide health care services as normal using established “downtime procedures,” and that patients are encouraged to keep all appointments.

Brian Gagnon, chief technology officer at Uprise Partners, a Maine-based infrastructure, security, and IT support company, said Monday that he’s seen a “huge uptick” in cyberattacks over the past five years, and it has not slowed down.

Gagnon said even customers who are well-protected, like hospitals and banks, are seeing attacks attempted on a daily basis.

He said from what he can tell, Central Maine Healthcare did the right things in its response to the suspicious activity.

“When you see things that are anomalies, the typical rule of thumb is to shut stuff down, reassess, and figure out where the attack might be coming from, if they’ve actually made it into the organization or are they just trying,” he said. “But seeing it and shutting things down means that they probably had the right software, hardware and platforms in place to catch this before it was a bigger thing.”

If organizations don’t have the proper systems in place, he said, it can sometimes take months to fully recover from an attack.

Gagnon said the hackers could be after data or financial gain, or simply trying to see if they are able to bypass security and gain access to the company’s system.

Gagnon said new artificial intelligence technology is also making it easier for hackers to try different attacks that they weren’t able to attempt in the past.