Comcast

In November 2015 the American telecommunications giant Comcast experienced a significant security incident where customer credentials appeared on darknet marketplaces. The breach exposed approximately 590000 customer accounts including email addresses and plaintext passwords. A subset of approximately 27000 records also contained physical household addresses. While Comcast stated their internal systems were not directly compromised it was determined that the data likely originated from phishing or credential stuffing attacks targeting their user base. The company forced password resets for all affected accounts to mitigate the risk of unauthorized access to customer services and billing information.