The resources found here are free to use.  Some are my creations while others are links to free resources that I’ve used.

Challenges:

Challenges

Security Checklists:

Windows_Security_Checklist

Hardening_Linux_Checklist

Presentations:

Protect Yourself From Malicious E-Mails (Created by /u/WeBredRaptors)

Scripts:

CCDC

Links:

Gary Kessler’s File Signatures

Tools:

Dislocker: FUSE driver to read/write Bitlocker-ed volumes under Linux/Mac OSX

Tutorials & Procedures:

Dislocker: Read/Write Bitlocker-ed volumes Under Linux tutorial (and lab)