Final answer:
Attackers use a variety of tools known as persistence mechanisms to maintain access to a system they've compromised, which include malware, rootkits, and scheduled tasks.
Step-by-step explanation:
The set of tools used by attackers to maintain access to a system are part of a broader category known as persistence mechanisms. Once a hacker gains access to a system, they employ various tools and techniques to ensure they can continue to control or monitor that system even after security measures are implemented or passwords are changed. Some common tools include malware, such as Trojans that provide backdoor access, rootkits that hide the attacker's presence on the system, and scripts or scheduled tasks that periodically grant access or send data to the attacker.
These tools are also designed to survive reboots and evade detection by antivirus software. The goal is to create a dependable method for an attacker to return to the compromised system. Attackers use these tools to siphon off sensitive data continuously, to make use of system resources for malicious purposes, or to gain a foothold in a network for future attacks. The best defense against such tools is a combination of strong security protocols, regular system updates, and user education to prevent initial breaches.