Подборка от NIST бесплатных и “недорогих” (less than $100) учебных онлайн-материалов по кибербезопасности: https://www.nist.gov/itl/applied-cybersecurity/nice/resources/online-learning-content
> The following links are for free and low-cost online educational content on topics such as information technology and cybersecurity. Some, not all, may contribute towards professional learning objectives or lead to industry certifications and online degrees.