In response to a pass-the-ticket attack alert, what should be your immediate action to mitigate impacts?

Isolating the infiltrated PC is a critical first step in responding to a pass-the-ticket attack alert. This strategy prevents any further unauthorized activities from that compromised machine, thereby containing the threat. By isolating the infected system, you effectively cut off the attacker's access to the network, which stops them from leveraging the compromised credentials to move laterally or execute additional attacks.

This action also allows for a safer analysis of the compromised system, where security teams can investigate the extent of the breach and gather evidence. Without this immediate isolation, the attacker may continue to exploit the environment, leading to greater damage or data loss.

In addressing the other options, while monitoring outbound traffic and auditing tickets are important parts of ongoing security practices, they do not address the immediate containment of the threat imposed by the compromised PC. Resetting passwords for all user accounts would also be a reactive measure that takes longer to implement and assumes that other credentials may not be simultaneously compromised. In the context of immediate response, isolating the compromised machine is the most effective action to take to mitigate immediate impacts from the attack.