designed to train security professionals in end-to-end network penetration testing. While many users look for a "PDF download" of the courseware, SANS maintains a strict copyright policy
Enrolled students can download digital versions of the textbooks. These are password-protected and watermarked with the student's ID.
If the cost of the full SANS course is a barrier, these free or low-cost alternatives cover similar "Network Penetration Testing" concepts: SEC560: Enterprise Penetration Testing - SANS Institute