Debian

What Server Logs Reveal About Attackers: Analyzing Suspicious Requests on Linux

Server logs provide critical insights into potential intrusions by recording events from the operating system, SSH authentication, and web applications. The guide explains how to examine Linux system journals with journalctl, review authentication logs on Debian and RHEL systems, and inspect Nginx access logs for unusual HTTP requests. Analysts learn to identify patterns such as rapid failed login attempts using multiple usernames from a single IP address, which may indicate brute-force or automated scanning activity. The article also covers counting the most active IP addresses with awk and sort commands while stressing the need to compare findings against normal traffic baselines. Additional recommendations include logging structured security events in JSON format with fields for timestamp, user ID, resource, and outcome, following OWASP guidelines. The text warns against storing sensitive data like passwords in logs and highlights limitations such as possible log tampering or unsynchronized server clocks. A practical seven-step investigation plan helps responders preserve evidence and verify hypotheses before taking action.

Pivoting in Legacy Hell: Navigating MIPS Servers, BusyBox, and 2014 Kernels During Internal Network Assessments

The article details a complete methodology for pivoting from an initial SSH compromise on an old Debian MIPS server to reach a hidden web admin panel inside a segmented network. It covers environment enumeration with commands like uname -a and ip route, followed by setting up a Chisel-based SOCKS5 proxy when standard SSH dynamic forwarding is disabled by server configuration. Scanning proceeds via proxychains with nmap using -sT, -Pn, and -n flags or by deploying static MIPS binaries directly on the host. Traffic is then routed through Burp Suite chained to the SOCKS proxy for password guessing against the web interface. The piece emphasizes practical constraints such as BusyBox limitations, kernel version incompatibilities with modern binaries, and the need for careful subnet identification. Readers are directed to replicate the full chain in the Forgotten Server task from the free White Hacker Profession course.

Selectel Launches Local AI Admin Agent aish in SELECTOS to Eliminate Cloud Data Risks

Selectel has introduced aish, a generative AI agent embedded directly into its SELECTOS server operating system. The solution allows system administrators to analyze incidents, review logs, and perform routine operations entirely on-premises without transmitting sensitive data to external cloud providers. Aish operates with a human-in-the-loop model, generating proposed commands and explanations that must be approved by an operator before execution. The primary goal is to support organizations bound by strict data-protection policies, including compliance with Russian Federal Law 152-FZ, by keeping all context within local infrastructure. SELECTOS is based on Debian and is distributed in ISO, QCOW2, and container formats for both cloud and dedicated servers. According to Kirill Dmitriev, Director of System Software at Selectel, the agent is intended to lower the entry barrier for Linux system administration while respecting restrictions on the use of foreign large language models.