What attackers spend their time and energy on attacking, and how they attack it, is the best indication of what works for them. Outside of targeted attacks for specific espionage, hacktivism, or warfare purposes, cybercrime is a volume game. Like most apex predators, cyber-attackers optimize their work to maximize their gains with the least amount of effort.

https://www.f5.com/labs/articles/threat-intelligence/spaceballs-security–the-top-attacked-usernames-and-passwords