[Vol-dev] Pythonisms and volatility-isms for structs

Edwin Smulders edwin.smulders at gmail.com
Wed Apr 17 08:24:48 CDT 2013


Followup question: can I use yara to match an integer(32) between a
specific range? I did not find this in the documentation, but that
does not always mean it is not possible.
For example, I want to find a pointer of which I know it's in the
0xBFFFF000-0xBFFFFFFF range. I suppose I could work around that by
searching for a hex string like "BF FF F? ??", but this does not feel
quite the same... Plus the ranges are not known beforehand, I have to
generate these rules.

On 16 April 2013 10:22, Edwin Smulders <edwin.smulders at gmail.com> wrote:
> On 16 April 2013 05:10, Michael Hale Ligh <michael.hale at gmail.com> wrote:
>> Hey Edwin,
>>
>> 1) It depends what type of pattern you're trying to match. If the pattern is
>> a simple byte string like "one" or "\x0d\x0a" you can just do
>> address_space.zread(address, size) == "one". If the pattern is a regular
>> expression you can also use the python re module (some examples in the
>> moddump and driverirp plugins). Also you can use yara for pattern matching
>> (there's a yarascan for windows and now a linux_yarascan plugin so look in
>> there for examples). Also if you do happen to want to search also, you can
>> use proc.search_process_memory(["one", "two"]) etc.
>
> Ahh, yara is more than I thought it was. I'll have a look at the
> rulesystem, see if it works for my purpose.
>
>>
>> 2) There is partial documentation on the wiki, see the 2.0 developers guide
>> https://code.google.com/p/volatility/wiki/VolatilityObjects20. Its obviously
>> a little dated since we're almost in 2.3 but most is still accurate. Or just
>> check out how its done in one of the other plugins like dumpcerts
>> (https://code.google.com/p/volatility/source/browse/trunk/volatility/plugins/dumpcerts.py)
>> which manually defines a vtype (the structure name, members, offsets, types)
>> and then creates an "object class" (inherits from obj.CType) to give it
>> custom methods etc.
>
> I'll have a look at the example in dumpcerts, thanks.
>
>>
>> Hope it helps,
>> MHL
>>
>>
>>
>> On Mon, Apr 15, 2013 at 8:37 AM, Edwin Smulders <edwin.smulders at gmail.com>
>> wrote:
>>>
>>> Hello all,
>>>
>>> I have arrived at an implementation part of my research and I was
>>> wondering if you have any advice or documentation on some "pythonisms"
>>> and "volatility-isms" I could be using to do this implementation.
>>>
>>> My question is two-fold:
>>>
>>> 1) I have acquired a small part of memory using read/zread and want to
>>> match (not search) this part of memory to a specific pattern. Do you
>>> know of any pythonisms I could be using, other than checking and
>>> matching byte by byte? Is there some type pattern I could use? I
>>> suspect I'll just have to evaluate a list of rules, but I figured I'd
>>> ask anyway.
>>> 2) Some parts of memory I am interested in are originally (C) structs,
>>> I'd like to map these to objects similar to the way this is done for
>>> structs like 'task_struct' and 'mm_struct', is there any documentation
>>> on the way this is done?
>>>
>>> If it matters, this is all in process address space.
>>>
>>> Cheers,
>>> Edwin
>>> _______________________________________________
>>> Vol-dev mailing list
>>> Vol-dev at volatilityfoundation.org
>>> http://lists.volatilityfoundation.org/mailman/listinfo/vol-dev
>>
>>


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