Cyber Resilience in the Financial Sector: Only 22% of Entities Pass a Ransomware Stress Test

Ransomware attack simulation (cyber-resilience stress test) conducted on 18 medium-sized financial entities (Fintechs, Digital Wallets, Niche Banks) in Argentina, Brazil, and Colombia demonstrated that only 22% critical services recovery under 4 hours without transactional data loss. The remaining 78% failed at least one success criterion: 45% had immutable backups that turned out to be compromised or inaccessible during simulation; 33% failed to restore banking core within the Recovery Time Objective (RTO) defined in their BIA; and 50% lacked effective crisis communication procedures, leading to news leaks before containment. Post-mortem analysis revealed that reliance on external IT providers for incident response is the most critical failure factor: entities managing response with internal teams had a 60% success rate, versus 10% for those fully dependent on third parties. A specific resilience stress test framework for the regional financial sector was developed.