Planned Parenthood Los Angeles says it's a victim of a ransomware attack.
In a letter posted on the California Attorney General's Office's website, Planned Parenthood says it first detected suspicious activity on Oct. 17, and an investigation determined that an unauthorized person had gained access on Oct. 8.
During that time, Planned Parenthood said patients' personal information was obtained, including name, address, diagnosis and procedure that may have been carried out.
According to NBC News, approximately 400,000 patients are impacted by the data breach.
"At this time, we have no evidence that any information involved in this incident has been used for fraudulent purposes," the letter to patients says.
Planned Parenthood is advising patients to review statements and contact their insurer or provider if they see charges for services they did not receive.