What does Frank's observation of multiple failed login attempts with the same password suggest?

The observation of multiple failed login attempts using the same password indicates a pattern associated with password spraying. In password spraying, an attacker tries a small number of commonly used passwords against many different accounts. This method minimizes the risk of account lockouts that typically occur when multiple failed attempts are made for a single account. Instead of focusing on a single account with numerous incorrect attempts, which can trigger security alerts, the attacker spreads the attempts across multiple accounts with the same common password.

This strategy is effective because many users tend to select common passwords, making it possible for the attacker to gain unauthorized access to one or more accounts without triggering alarms. Therefore, the signs of multiple failed attempts with the same password strongly align with the behaviors characteristic of password spraying rather than the other attack types presented, which involve different methods and motives.