Blog
Networking, ports, and security guides.
Ports tied to trojans, backdoors and C2 — NetBus, Back Orifice, ingreslock, Meterpreter and abused legit services — and how to detect a compromise.
A scannable reference of common TCP and UDP ports grouped by purpose — web, mail, file transfer, remote access, databases, and infrastructure.
Check open and listening ports on Windows, Linux, and macOS, map a PID to its process, and scan a remote host with Nmap. Commands you can copy-paste.
Learn how to close a port the right way: stop the service vs firewall it. Covers Windows Firewall, ufw, firewalld, iptables, and disabling services safely.
Learn how to scan TCP and UDP ports with Nmap: install, port selection, SYN vs connect scans, version detection, NSE scripts, and output formats.
The internet-facing ports attackers hit first — RDP, SSH, SMB, databases — and the single most important hardening step for each.
A practical guide to ports you should never expose to the internet — SMB, RDP, Telnet, databases and more — with the risk and a safer alternative for each.
A clear comparison of TCP and UDP: handshakes, reliability, headers, real-world use cases, and why UDP fuels amplification DDoS attacks.
How reflection and amplification DDoS attacks abuse UDP services like DNS, NTP, SNMP, SSDP and Memcached — with amplification factors and how to avoid being a reflector.