A client tool that interfaces with a server we host (Thanks @IOActive) with over 200000 fragments of relocation data that is compiled from various PE files. This ensures when extracting data from memory dumps that you can match memory to disk files precisely. I've targeted @dotnet/coreclr and @dotnet/wcf under the hood.
This code target's coreclr to maximize portability. Most development has taken place on Windows so there is a little bit of test that needs to be done for Linux, OSX, FreeBSD, etc... I'll likely be implementing some workarounds for the WCF SOAP API calls to ensure an alternative mechanism is in place to contact the server.
I'm done with this code for a while. I attached an example report from WinMerge from a binary dumped with Volatility then block hashed to 512 bytes sizes with Tiger 192 (the same as BlockWatch currently uses :).
Extract relocations from .pdb's as an alternative for MS files.
As you can see Reloc enabled the dumped binary to match almost exactly.
Quick note to dumper writers
If your using Reloc make sure you validate precisely the sections so your not accidentally missing code due to alignment/code caves.
Next will be a command for delocating a dumped binary. That is, an image
extracted from memory to disk (one-to-one) delocation so that any position
dependent instructions/references are fixed (delocated) to their original
values. Null pages are accounted for since we can not depend on a runtime
page fault to cause all of a given binary to load. This does add a bit of
complexity to the DeLocate routine. It's currently implemented unsafe since
ported from C, will be moving to safe soon.
Delocation code is in place however is only exposed to API callers not CLI.
Program.cs has a set of upcoming features, feel free to contact or use github to give us some requests. If nobody else does it I'll try to figure out some python to integrate into @volatility.
.NET coreclr restore/run like so;
dnu restore dnx [command] [args] dnx commands Error: Unable to load application or execute command 'commands'. Available commands: Reloc, Extract.
Not all of our routines are optimized yet, it seems like the async IO in coreclr is doing really well, as you can see below, pretty respectable performance for non-native code nearly 3500 read/writes in less than 13 seconds.
Example: dnx run Extract c:\windows\system32 d:\temp\test
X:\Reloc\src\Reloc>dnu restore Microsoft .NET Development Utility CoreClr-x64-1.0.0-rc2-16249 ... Writing lock file X:\Reloc\src\Reloc\project.lock.json Restore complete, 2714ms elapsed X:\Reloc\src\Reloc>dnx run Extract c:\windows\system32 d:\temp\test Scanning folder c:\windows\system32 and saving relocs into d:\temp\test. ... extracted relocs into d:\temp\test\ztrace_maps.dll-180000000-564D22CC.reloc size 512 processing time: 00:00:12.9261101 Compiled 3493 new .reloc data fragments
This command string is a little out of control. I'll add some switches to make it a bit easier or something ;). Specifying "dnvm exec default dnx " is an alternative way to get the runtime version your looking for.
Delocate will attempt to automatically rebuild the complete executable on disk from memory. The only differences should be;
- Data section, if anybody has idea how to reverse the data, that will be interesting.
- .reloc missing, it dosent really matter since you download or captured .reloc locally in the first place, you can cat >> the reloc to the end of your new binary if you would like.
- There may be some artifacts regarding the resources depending on the application specifics. I havent looked at resource handling in a minute.
dnvm exec default dnx DeLocate d:dumped.msctf.dll d:msctf.dll-10000000-564D1E7B.reloc 77740000 d:delocated.msctf.dll False
Example: dnx Reloc True ntdll 51DA4B7D
After you clone into a directory
c:\git>git clone https://github.com/ShaneK2/Reloc.git Cloning into 'Reloc'... remote: Counting objects: 18, done. remote: Compressing objects: 100% (16/16), done. remote: Total 18 (delta 2), reused 13 (delta 1), pack-reused 0 Unpacking objects: 100% (18/18), done. Checking connectivity... done. c:\git>cd Reloc\src\Reloc c:\git\Reloc\src\Reloc>dnu restore Microsoft .NET Development Utility CoreClr-x64-1.0.0-rc2-16237 CACHE https://www.nuget.org/api/v2/ CACHE https://ci.appveyor.com/nuget/gemini-g84phgw340sm/ CACHE https://www.myget.org/F/aspnetvnext/api/v2/ CACHE https://www.myget.org/F/dotnet-core/api/v3/index.json Restoring packages for C:\Temp\testing\Reloc\src\Reloc\project.json CACHE https://www.nuget.org/api/v2/FindPackagesById()?id='System.Reflection.TypeExtensions' CACHE https://ci.appveyor.com/nuget/gemini-g84phgw340sm/FindPackagesById()?id='System.Reflection.TypeExtensions' CACHE https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?id='System.Reflection.TypeExtensions' CACHE https://www.myget.org/F/dotnet-core/api/v3/flatcontainer/system.reflection.typeextensions/index.json Writing lock file C:\Temp\testing\Reloc\src\Reloc\project.lock.json Restore complete, 973ms elapsed c:\git\Reloc\src\Reloc>dnx Reloc True ntdll 51DA4B7D Contacting, dest file [ntdll-?####?-51DA4B7D.reloc.7z]: 64bit:True, Region(dll):ntdll, TimeDateStamp:51DA4B7D. Downloaded to NTDLL.DLL-78E50000-51DA4B7D.reloc.7z, size 905. c:\git\Reloc\src\Reloc>dir NTDLL.DLL-78E50000-51DA4B7D.reloc.7z Directory of \git\Reloc\src\Reloc 11/27/2015 02:52 PM 905 NTDLL.DLL-78E50000-51DA4B7D.reloc.7z
Simply extract and use the data to establish high assurances in your forensics process.
- Fixe'dm all ;)
For some reason when the last word is written out (the buffers are being delocated) they do not appear back on disk. Currently I modify the delocation buffer in-place so in the event your not using disk files and call this method w/o hitting the disk we don't need to waste too much, it's probably a worthless micro-opt anyhow.