 Every day, European citizens, businesses and governments carry out financial transactions through the financial system. Today we live in an age where cyber attackers are more sophisticated and more persistent. Cyber space has become the new front for warfare. Within this context, the European Central Bank has a pivotal role in ensuring the financial stability of the financial system and enhancing the cyber resilience of it. As a result, in 2018, the European Central Bank published Tiber EU, threat intelligence-based ethical red teaming. These tests are conducted by financial institutions when they hire ethical hackers to carry out simulated attacks against them so that these institutions can identify their weaknesses and make improvements going forward. This is ethical hacking.