offsec.tools - A vast collection of security tools

ATT&CK TTP Database

https://github.com/cmndcntrlcyber/attck

https://github.com/cmndcntrlcyber/one-attck-per-time

MalAPI.io

Filesec.io

LOTS Project - Living Off Trusted Sites

Living Off the Living Off the Land

WADComs

LOLBAS

GTFOBins

LOLDrivers