In a network assessment, which is a common indicator of a successful brute-force attack?

A common indicator of a successful brute-force attack is the locking of accounts due to password policy. This typically occurs when multiple unsuccessful login attempts are made in a short period. Most systems are configured with security measures that lock an account after a specific number of failed login attempts to protect against unauthorized access. Once the threshold is reached, the account gets locked as a security precaution, signaling that there may have been a brute-force attempt to gain access by trying many different passwords.

The other options, while they may indicate some type of unusual activity, are not direct indicators of a successful brute-force attack. Frequent successful logins could suggest legitimate access or another form of compromise. Changes in system configurations may occur for numerous reasons, including administrative actions. Multiple accounts accessing the same resources might result from legitimate sharing practices, rather than indicating a brute-force attack. Understanding these indicators is crucial for identifying and mitigating security threats in a network environment.