It stands for Capture The Flag, in these exercises it usually means completing a series of reverse engineering scenarios exploiting vulnerabilities in a simula

It stands for Capture The Flag, in these exercises it usually means completing a series of reverse engineering scenarios exploiting vulnerabilities in a simulated environment or possibly obtaining and holding root access to a host while others continue to search for and attack the host. The CTFTime FAQ has more information: https://ctftime.org/ctf-wtf/ https://ctftime.org/ctf-wtf/