Everest Ransomware Hits TSYS: Attack Analysis, Payment Risk, and a Practical Defense Playbook
On May 2, 2026, the Everest ransomware group claimed responsibility for a breach of TSYS, a major U.S. payment processor that handles billions in transactions and serves millions of end customers through banks and merchants. The attackers posted proof-of-compromise on a dark web leak site and threatened to release up to 500 GB of sensitive…