On 09/23/2011 03:11 PM, rohan puri wrote:
On Fri, Sep 23, 2011 at 2:43 PM, Abhijit Pawar <[email protected]
<mailto:[email protected]>> wrote:
On 09/23/2011 02:04 PM, rohan puri wrote:
On Fri, Sep 23, 2011 at 2:00 PM, Abhijit Pawar
<[email protected] <mailto:[email protected]>> wrote:
On 09/23/2011 01:01 PM, Rajat Sharma wrote:
Untidy way : -
Yes, you can do that by registering a new binary
format handler. Whenever
exec is called, a list of registered binary format
handlers is scanned, in
the same way you can hook the load_binary&
load_library function pointers
of the already registered binary format handlers.
Challenge with this untidy way is to identify the correct
format, for
example if you are interested in only hooking ELF format,
there is no
special signature withing the registered format handler
to identify
that, however if one format handler recognizes the file
header, its
load_binary will return 0. This can give you the hint
that you are
sitting on top of correct file format. Long time back I
had written
the similar module in Linux to do the same, but can't
share the code
:)
-Rajat
On Thu, Sep 22, 2011 at 3:14 PM, rohan
puri<[email protected]
<mailto:[email protected]>> wrote:
On Thu, Sep 22, 2011 at 1:53 PM, Abhijit
Pawar<[email protected]
<mailto:[email protected]>>
wrote:
hi list,
Is there any way to hook the exec system call on
Linux box apart from
replacing the call in System Call table?
Regards,
Abhijit Pawar
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Tidy way : -
You can do that from LSM (Linux security module).
Untidy way : -
Yes, you can do that by registering a new binary
format handler. Whenever
exec is called, a list of registered binary format
handlers is scanned, in
the same way you can hook the load_binary&
load_library function pointers
of the already registered binary format handlers.
Regards,
Rohan Puri
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So If I use the binary format handler, then I can hook the
exec call. however I need to register this. Does that mean
that I need to return the negative value so as to have actual
ELF handler to be loaded?
Regards,
Abhijit Pawar
Read this, http://www.linux.it/~rubini/docs/binfmt/binfmt.html
<http://www.linux.it/%7Erubini/docs/binfmt/binfmt.html> this
might help
Regards,
Rohan Puri
Thanks Rohan. I tried creating a hooking module on the similar
line. I am able to load the module but whenever I am launching any
application , its load_binary is not being called.
here is the source for the module attached.
Regards,
Abhijit Pawar
Hi Abhijit,
I have made the change, try to compile and execute this code, it works.
Also, I am just curious enough to know that where do you need to do
this hooking.
Regards,
Rohan Puri
Hi Rohan,
I have been looking at Windows worlds ability to support DLL Injection
and API hooking. I was just wondering if this could be something to be
done in Linux as well. I am not sure if there is any special use of
this module apart from learning the binary handler. May be it could be
used as a security module for your own binary handler.
Regards,
Abhijit Pawar
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