New set of challenges: Microsoft Windows kernel

A new series of challenges in Windows Kernel is now available! The first challenge is open to everyone, while the others are temporarily exclusive to premium members and will be open to the public on the following dates:

• WinKern x64 - shellcoding: token stealing: public
• WinKern x64 - Stack buffer overflow advanced - ROP: February 24
• WinKern x64 - Use After Free: March 24

A big thank you to Synacktiv, __syscall for their challenges!
Another big thank you to und3ath & Ech0 for their work on the architecture of these exercises.