What are Three most malicious attacks of default account vulnerabilities?

Three of the most malicious attacks exploiting default account vulnerabilities are credential stuffing, where attackers use default usernames and passWords to gain unauthorized access to accounts; privilege escalation, where attackers exploit default accounts to gain higher access levels within a system; and data exfiltration, where attackers leverage default accounts to steal sensitive information. These attacks are particularly effective because many users fail to change default credentials, leaving systems open to exploitation. Organizations must prioritize securing default accounts to mitigate these risks.