Brute-force

Brute-force attacks occur when an attacker repeatedly attempts different usernames or passwords in an attempt to gain unauthorized access to an account. Automated tools are often used to send these requests quickly, allowing attackers to go through large lists of credentials and common passwords. T-Mobile faced a breach in 2021 that stemmed from a brute-force attack, allowing attackers access to the personally identifiable information (PII) of over 50 million T-Mobile customers.