I am not checking them at regular intervals but i hope they still work and are relevant.
Please provide me some feedback if for some reason they are not relevant or working anymore.
- https://lab.pentestit.ru/ (Similar to OSCP labs.)
- https://picoctf.com/ (Designed for high school students)
- https://microcorruption.com/login (introduction to low-level reverse engineering, specifically on an MSP430)