FastFinder is a lightweight tool designed for threat hunting, live forensics, and triage on both Windows and Linux platforms. It focuses on endpoint enumeration and suspicious file finding based on various criteria such as file path/name, checksums, string content match, and YARA rules. It has been tested in real cases in multiple CERT, CSIRT, and SOC use cases, with examples including real malwares and vulnerability scan examples. Compiled releases are available, but compiling from sources may be tricky due to dependencies on go-yara and CGO compilation.