This blog post, aimed at security practitioners, provides an in-depth understanding of Windows access tokens, crucial for detection engineering. It explains the relationship between logon sessions and access tokens, emphasizing that access tokens act as proxies for logon sessions, storing security settings and privileges. The article details how access tokens are linked to logon sessions via a 64-bit locally unique identifier and how these tokens can be adjusted without affecting other processes. It also covers network authentication, highlighting the role of access tokens in impersonation, where different threads can assume different security contexts. The post notes that impersonation is used to handle client requests in multi-threaded applications, emphasizing the importance of understanding these mechanisms to detect and prevent token manipulation. The piece concludes with a preview of the next part in the series, which will explore how attackers exploit Windows functionality to move laterally and compromise Active Directory domains.