KRH said 130,000 patients could have had been exposed after several of its employees were victims of an email that led them to unknowingly providing their hospital login credentials to hackers over the summer.
This email attack could also affect any of KRH's clinics such as Brendan House and KRH oncology.
Director of Communications and Marketing Mellody Sharpton explained that while North Valley hospital's emails were not directly affected, there may be some patients who seek treatment at North Valley as well as KRH that will be.
While the initial attack was this summer, Sharpton explained the hospital just learned 10 days ago exactly which patients may or may not have been exposed.
She said patients affected will receive a letter with instructions on how to proceed within the next few weeks.
A year of free monitoring services are provided for those impacted and if anyone has any questions there is a dedicated call center at 1-877-514-0850.