Persistence consists of techniques that adversaries use to maintain their foothold on systems across restarts. Techniques used for persistence include any access, action, or configuration changes that allow attackers retain access on systems. Persistence is one of the more sought-after techniques of an attacker. Every 3 techniques out of top 10 usedby Adversaries belong to Persistence. We leveraged data from MITRE ATT&CK and open source cyber threat intelligence to understand how adversary achieves persistence. We created Tenacity, a light-weight adversary emulation tool that emulates over 30+ persistence techniques using 100+ procedures employed by attackers in the wild. Using this tool the organizations and individuals can quickly validate the risk posture and exposure of their business as well as the performance of the existing security solutions.