diff --git a/README.md b/README.md index 7b86e86..a22079a 100644 --- a/README.md +++ b/README.md @@ -3,4 +3,40 @@ reverse engineering of bedaisy.sys (battleyes kernel driver). By registering on image load callbacks and IAT hooking BEDaisy's `MmGetSystemRoutineAddress` we can simply hook any imports we want and have control flow over subsequent functions. - \ No newline at end of file + + +# APCS + +The below function will be executed in each thread that bedaisy registers an APC on. + +```cpp +__int64 __usercall apc_callback@(char _CL@, char _BH@, __int64 *a3@) +{ + __int64 v4; // rbx + + __asm { rcl bh, cl } + v4 = *a3; + *(_DWORD *)(v4 + 2160) = RtlWalkFrameChain(*a3 + 0x70, 256i64, 0i64); + return KeSetEvent(v4 + 88, 0i64, 0i64); +} +``` + +Registeration of APCS: + +```cpp + status = PsLookupThreadByThreadId(thread_id, &some_pethread); + v17 = 0; + if ( (int)status >= 0 ) + { + allocated_pool = ExAllocatePool(0x200i64, 0x878i64); + allocated_pool_1 = allocated_pool; + allocated_pool_2 = allocated_pool; + if ( allocated_pool ) + { + allocated_pool_plus_58 = allocated_pool + 0x58; + KeInitializeEvent((PRKEVENT)(allocated_pool + 0x58), NotificationEvent, 0); + __asm { rcl cx, 0C6h } + LOBYTE(v77) = 0; + KeInitializeApc(allocated_pool_2, some_pethread, 0i64, j_apc_callback, 0i64, 0i64, v77, 0i64); + if ( (unsigned __int8)KeInsertQueueApc(allocated_pool_2, allocated_pool_2, 0i64, 2i64) ) +``` \ No newline at end of file