Whaling attack
A whaling attack is a method used by cybercriminals to masquerade as a senior player at an organization and directly target senior or other important individuals at an organization, with the aim of stealing money or sensitive information or gaining access to their computer systems for criminal purposes.
A whaling attack is essentially a spear-phishing attack but the targets are bigger - hence whale phishing. Where spear-phishing attacks may target any individual, whaling attacks are more specific in what type of person they target: focusing on one specific high level executive or influencer vs a broader group of potential victims.
Cybercriminals use whaling attacks to impersonate senior management in an organization, such as the CEO, CFO, or other executives, hoping to leverage their authority to gain access to sensitive data or money. They use the intelligence they find on the internet (and often social media) to trick employees - or another whale - into replying with financial or personal data.