A walkthrough of klezVirus' "Callback hell" — a technique that hides callback frames from stack inspectors by combining tail-calls, forward and backward proxy frames, and a chained thread-pool dispatcher, while still recovering the callee's return value via a MOV [REG], RAX gadget. Published under CC BY 4.0 and republished here in full, with all original figures, assembly listings, and the POC video. core-jmp.org/2026/05/callba…

@bytecodevm What a nice low-level trickery :), I would love to see unaligned stack obfuscation, to damage the RSP/ESP (or rsp,1) and emulate every push/pop/call to go via mov [rsp-1],rax etc I think EDR tools and CPU emulators would go insane. Plus FPU based VM engine.