Possibly login information became available when customers accidentally installed malware, or were exposed to phishing or previous major data breaches. “We’re taking this seriously and we’re working to get this fixed for those customers who may have been impacted, but the vast majority of information out there was invalid,” a Comcast company spokesperson said. The marketplace ad has generated a single sale since it was posted. This year, hundreds of millions of records have been stolen by hackers and malicious actors, including healthcare companies, credit agencies acting on behalf of phone carriers, and even the federal vetting agency for government workers.