OSINT for Incident Response (Part 1)

This practitioner blog demonstrates how quick OSINT sweeps (nslookup, DNSDumpster, Shodan, Censys, LeakIX) can accelerate DFIR: in the featured case a firewall migration introduced a NAT misconfiguration that exposed RDP/SMB to the internet, enabling attackers to install remote-access software and deploy ransomware. The author shows using external scans and screenshots plus internal logs (e.g., Windows 4625 events) to establish timelines, identify patient zero, and support remediation and vendor accountability, and advocates making OSINT a routine part of incident response.