A malicious actor opted to compromise the eccouncil video

Full Certification Question

A malicious actor opted to compromise the passwords utilized in industrial control systems. In this endeavor, the attacker implemented a looping strategy to unveil these passwords. The approach involved checking one character at a time to determine if the first character input was accurate. If the initial character was correct, the attacker persisted in the loop to assess consecutive characters; otherwise, the loop was terminated. Additionally, the attacker assessed the time taken by the system to complete a full password authentication process, allowing inference regarding the number of correctly entered characters. What is the attack technique utilized by the attacker to decipher the passwords of the industrial control systems?