In this lab walkthrough, we will analyze a security incident involving an unauthorized intrusion into a Linux-based system. The attacker employed a variety of tactics, including brute-force authentication, privilege escalation, and persistence mechanisms, ultimately gaining control over the compromised system. By carefully examining system logs, command histories, and forensic artifacts, we will reconstruct the attacker's actions and identify the techniques used to compromise multiple user accounts.
The investigation begins by identifying the initial point of entry and determining how the attacker gained access to the system. From there, we will explore the methods used to escalate privileges, create backdoors for persistence, and execute malicious scripts. By analyzing authentication logs, newly created user accounts, and unauthorized system modifications, we will uncover the full extent of the attack.
Further examination will reveal how the attacker leveraged existing system vulnerabilities and misconfigurations to maintain access and execute commands stealthily. Additionally, forensic analysis of cron jobs, bash histories, and network activity will shed light on how the attacker established persistence and exfiltrated sensitive information. One of the key objectives of this investigation is to determine whether any form of data exfiltration took place and, if so, to recover any stolen information.
Throughout this walkthrough, we will utilize various Linux command-line tools to extract and interpret forensic evidence. The goal is not only to understand the attack but also to develop effective defensive strategies to prevent similar incidents in the future. B