Over 1 Million Americans Exposed in Major Healthcare Data Breach

A massive cyberattack on a third party vendor serving healthcare firms has put more than one million Americans at risk. The incident affected Medical Computer Business Services, known as MCBS, after unauthorized users breached their computer network. Officials confirmed that the total number of impacted individuals stands at 1,261,464.

MCBS first noticed unusual system activity in September 2025. Following a lengthy forensic investigation, the firm discovered that attackers managed to steal a large volume of sensitive files. The stolen information includes full names, home addresses, Social Security numbers, dates of birth, and detailed medical records. MCBS provides vital administrative and backend support for various hospitals, private practices, and medical groups.

Affected individuals are now receiving formal notifications alongside offers for free identity protection services. Company representatives state they have not found any evidence of identity theft or misuse of the stolen data so far. Security experts advise anyone receiving a notice to monitor their financial accounts closely and remain alert for potential phishing attempts.