Millions of Comcast Xfinity subscribers' personal data, including usernames, hashed passwords, names, contact details, last 4 digits of social security numbers, dates of birth, and secret questions and answers. The data was likely stolen after Comcast's systems were accessed without authorization in October. In a privacy breach notification, Comcast stated approximately 35.9 million user IDs were affected. Comcast disclosed it discovered suspicious activity on October 25 during a routine cybersecurity exercise and subsequently determined the unauthorized access was due to the Citrix vulnerability.