Clark School study quantifies rate of hacker attacks of computers with Internet access. Researchers discovered which usernames and passwords are tried most often, and what hackers do when they gain access to a computer. The most common password-guessing ploy was to reenter or try variations of the username. “Root” was the top username guess, 12 times as often as “admin” and “root” The study was conducted by Michel Cukier, Clark School assistant professor of mechanical engineering and affiliate of the Center for Risk and Reliability.”]
Source: https://eng.umd.edu/news/story/study-hackers-attack-every-39-seconds