July 15, 2014
Microsoft did nice work related to callback mechanism, to avoid nasty patching across kernel, and support monitoring in clean way. Currently we can use, among others, for example callbacks on loading new image, process, thread, opening & duplicating handles, dropping files etc. For monitoring network communication you can attach to some device drivers, which is cleaner than hooking, but still does not cover as much as i want to. And there comes ALPC, because even resolving host comes through, and when you are able to recognize it ..
In april I attend awesome training at Syscan, training was led by Alex Ionescu. Among a lot of deep kernel stuffs, there was deeply covered ALPC mechanism, which is the point of this blog – post. Nice presentation about ALPC, which I really recommend to read : All about the RPC, LRPC, ALPC, and LPC in your PC
March 27, 2014
When it comes to working with memory of process, it comes handy to have information about whole address space of process, to do not touch PAGE_GUARD, knowing exec and writable pages, etc.
For that purpose i already implemented VadWalker in my kernel common repo, and also use it in DbiFuzz frmwrk. But recently i come accross some ideas, how to improve my recent approach and do it more efficiently and kinda smarter.
August 4, 2013
I started a bit researching around fuzzers, fuzzing techniques and practices. As i study materials about fuzzing, code (node / edge) coverage approach quickly impressed me. But for this method is essential to have a good dbi. Pin or valgrind are good solutions, but will i try to make it in lightweight way – specificated for further fuzzing needs.
Already implemented features :
- BTF – Hypervisor based
- PageTable walker
- VAD walker
- full Process control [images, threads, memory]
- Syscall monitoring – implemented process virtual memory monitor
Fuzzing, GongFu, Intel® VT-x x64, Virtualization
June 22, 2013
Virtualization can be utilized to reach various goals as monitoring system, system resources and applications as well. It can be used for full system virtualuzation, but i like apporach using it just as a tool too . This post will shortly cover implementation of mini-hypervisor (which is now available on github) for intel vt-x on x64 platform, and demonstrate concept how-to-use-it.
June 4, 2013
In this post i will take a look at PatchGuard, at classic scenario of bypassing this protection and also at little bit diferent one. I will also examine new way (bust most probably not new, just reinvented cause it is too obvious and quite efective) how to locate & abuse page guard context and its behaviour.
typedef struct _KDPC
volatile USHORT Number;
__volatile PVOID DpcData;
} KDPC, *PKDPC, *PRKDPC;
PoC and some explanation of code, of its weaknes and points to research are included