George Washington University Hospital was affected by a cyberattack that targeted its majority owner and forced facilities to move some operations offline, a spokeswoman confirmed.

Universal Health Services, one of the nation’s largest health-care providers, with more than 400 locations, has been dealing with the cyberattack since Sept. 26, spokeswoman Jane Crawford said Friday in an email. UHS oversees GWU Hospital; the university is a partial owner.

Electronic medical records were not directly affected by the network security problem that officials said was caused by malware.

There’s no indication that patient or employee data has been accessed, officials said in a statement Thursday.

In an earlier statement, dated Tuesday, the company said the cyberattack could temporarily disrupt clinical and financial operations, but it did not provide details on how many medical facilities were affected.

UHS shut down its network shortly after the attack was detected. The company is in the process of restoring online operations, but Crawford did not answer questions about when the problem is expected to be resolved.

Despite the network troubles, officials said, patients could still be treated safely, according to the statement that was issued Thursday.

Employees at GWU Hospital and other UHS-managed facilities have been relying on backup methods, like documenting information offline.