https://tryhackme.com/r/hacktivities/search?kind=all&difficulty=easy&order=newest&roomType=challenge&contentSubType=free&searchText=&page=1&status=not-completed

https://app.hackthebox.com/

https://play.picoctf.org/practice

https://codeby.games/ [RUSSIAN]

https://ctftime.org/ctfs

https://exploit.education/protostar/

https://www.vulnhub.com/