The binary doesn't execute standard x64 instructions for its main logic. Instead, it uses a custom-built virtual machine with its own bytecode and registers.
The zip contains the executable which, when run, decrypts and executes further stages in memory.
Navigating the custom VM loop in IDA Pro or Ghidra. Analysts look for the "fetch-decode-execute" cycle to understand how the custom bytecode is processed.
Using x64dbg to trace the decryption routines. The challenge often requires "dumping" decrypted buffers from memory for further inspection.
Mandiant usually publishes a PDF with the intended solution path for every challenge.
Independent researchers often post highly detailed blogs on these challenges.
A "good" write-up for this challenge typically follows these stages:
The challenge involves a 64-bit Windows executable that acts as a custom "loader." Its primary goal is to execute a hidden payload, but it employs several layers of complexity to thwart standard analysis: