What type of automatic remediation can be performed by the PTA in case of a suspected credential theft security event?

The correct answer is the action that pertains to "Password Change" as an automatic remediation step in the event of a suspected credential theft.

In scenarios where there is a suspected credential theft, it is crucial to secure user accounts quickly to mitigate risks. Changing the password is a direct method to prevent unauthorized access from continuing. Automatic password change effectively limits the adversary's ability to exploit stolen credentials, as it invalidates the compromised password, enabling the legitimate user to re-establish secure access. This action not only protects the user account but also serves to notify users that their credentials may have been compromised, prompting them to be more vigilant about their account security.

In evaluating the other choices, password reversal is typically not a valid corrective action as it doesn't align with standard security practices, which focus on enhancing security rather than reverting back to previous states. Account lock might prevent access but doesn't directly counteract the issue of stolen credentials in a proactive manner. Session timeout could be beneficial but may not be sufficient on its own for addressing the fundamental issue of secured access after a credential compromise. Thus, changing the password serves as a more comprehensive protective measure in this context.