Scheduled tasks are a common method used by attackers to maintain persistence on a system. They can be easily set up to execute payloads or malicious scripts at specific times or intervals and are often overlooked during system audits and monitoring, making them less likely to be detected compared to more obvious methods like Trojans or backdoors that can trigger antivirus or intrusion detection systems. Other options like daemons and Trojans are more detectable due to the artifacts they leave and their common signatures. Upgrading a restrictive shell doesn't directly contribute to persistence