[OWASP_PHPSEC] [Offtopic] Decrypting information out of an image

Shivam Dixit shivamd001 at gmail.com
Fri Oct 4 22:29:48 UTC 2013


Thank you :)


On Fri, Oct 4, 2013 at 7:41 PM, Maarten Hoogveld <m.hoogveld at elevate.nl>wrote:

> I kinda like the fact that you found something which they probably didn't
> know was there :)
>
>
> --
> Met vriendelijke groet, Kind regards,
> Maarten Hoogveld
> Elevate BV
>
>
> On Fri, Oct 4, 2013 at 4:09 PM, Shivam Dixit <shivamd001 at gmail.com> wrote:
>
>> Thank you guys ! Maarten's and abhishek's method is definitely better.
>>
>>
>> On Fri, Oct 4, 2013 at 7:16 PM, Abhishek Das <das.abhshk at gmail.com>wrote:
>>
>>> +1 to Maarten's method. It's visible even if you tilt your screen a bit
>>> and see. All it needs is a bit of in-browser -webkit-filter tweaking or
>>> levels in gimp adjustment.
>>>
>>>
>>> On Fri, Oct 4, 2013 at 7:13 PM, Maarten Hoogveld <m.hoogveld at elevate.nl>wrote:
>>>
>>>> I found the same thing in a different way actually. I just played
>>>> around with the color-levels in gimp, to make the difference between white
>>>> and almost-white (very light grey) visible. It can emphasize the contrast.
>>>> I saw the grid clearly then, but also saw the text
>>>> flag{youKnowWhosTheBoss} in the image itsself. (See for youself<http://imgur.com/IniFKKK>
>>>> )
>>>> I think that whould have been what you were supposed to find :)
>>>> They probably left some meta data lying around :)
>>>> Nice find!
>>>>
>>>>
>>>>
>>>> --
>>>> Met vriendelijke groet, Kind regards,
>>>> Maarten Hoogveld
>>>> Elevate BV
>>>>
>>>>
>>>> On Fri, Oct 4, 2013 at 2:53 PM, Minhaz A V <minhazav at gmail.com> wrote:
>>>>
>>>>> youKnowWhosTheBoss :)
>>>>>
>>>>>
>>>>> On Fri, Oct 4, 2013 at 5:21 PM, Shivam Dixit <shivamd001 at gmail.com>wrote:
>>>>>
>>>>>> Hello all
>>>>>>
>>>>>> Thank you for your suggestions. I was able to solve the question and
>>>>>> it was much *simpler* than I was expecting and it only required *reading
>>>>>> meta data* and finding the value of "*flag*". I was able to scan
>>>>>> through meta data using a tool provided on this website :
>>>>>>
>>>>>> http://imgops.com/
>>>>>>
>>>>>> The name of tool is *metapicz. *
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Fri, Oct 4, 2013 at 3:26 PM, Minhaz A V <minhazav at gmail.com>wrote:
>>>>>>
>>>>>>> My bad just googled "stenography" and got to know Abbas and Maarten
>>>>>>> were suggesting the same..:D
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Oct 4, 2013 at 3:21 PM, Maarten Hoogveld <
>>>>>>> m.hoogveld at elevate.nl> wrote:
>>>>>>>
>>>>>>>> Just a tip to prevent you spending hours looking at difficult to
>>>>>>>> read text, it's possible to solve in under 5 minutes.
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Met vriendelijke groet, Kind regards,
>>>>>>>> Maarten Hoogveld
>>>>>>>> Elevate BV
>>>>>>>>
>>>>>>>>
>>>>>>>> On Fri, Oct 4, 2013 at 11:47 AM, Minhaz A V <minhazav at gmail.com>wrote:
>>>>>>>>
>>>>>>>>> Shivam,
>>>>>>>>> out of curiosity I downloaded this image from doc and opened it in
>>>>>>>>> notepad++ and while going through its source I found something strange.
>>>>>>>>> It had a lot of English words which included those like *Typeenum,
>>>>>>>>> bottomOutsetlong, printOutputOptions*
>>>>>>>>> which are not available in normal images so just have a look if
>>>>>>>>> this can be of any help (otherwise I doubt this has something to do with
>>>>>>>>> Photoshop).
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> Minhaz
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Fri, Oct 4, 2013 at 2:40 PM, Maarten Hoogveld <
>>>>>>>>> m.hoogveld at elevate.nl> wrote:
>>>>>>>>>
>>>>>>>>>> Hi Shivam,
>>>>>>>>>>
>>>>>>>>>> You could dive into converting the image in a 2-D array of
>>>>>>>>>> intensity values and maybe even extracting the R, G and B channels
>>>>>>>>>> separately. Then analyze that data for patterns and slight deviations which
>>>>>>>>>> could indicate steganography of some sort.
>>>>>>>>>> However, I would first pick the low hanging fruit and just look
>>>>>>>>>> at the image. I see that the image is white with a very light grid. You
>>>>>>>>>> could try to load the image in gimp <http://www.gimp.org/> or
>>>>>>>>>> paint.net <http://www.getpaint.net/> and see if you can see
>>>>>>>>>> something more when you zoom in so you can see individual pixels or adjust
>>>>>>>>>> contrast, etc.
>>>>>>>>>> Good luck!
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Met vriendelijke groet, Kind regards,
>>>>>>>>>> Maarten Hoogveld
>>>>>>>>>> Elevate BV
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Thu, Oct 3, 2013 at 10:08 PM, Shivam Dixit <
>>>>>>>>>> shivamd001 at gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> Hello all
>>>>>>>>>>>
>>>>>>>>>>> Not much discussions on this list nowdays, so I thought of
>>>>>>>>>>> sharing one of the questions which I came across recently in college CTF,
>>>>>>>>>>> and was unable to solve it.
>>>>>>>>>>>
>>>>>>>>>>> The question is the image below :
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> https://docs.google.com/file/d/0B4G8EjUmqNchUlg1cGI3UFl4SEE/edit?usp=sharing
>>>>>>>>>>>
>>>>>>>>>>> (Image is white, with some grids)
>>>>>>>>>>>
>>>>>>>>>>> I have to decrypt some information out of it. I am not able to
>>>>>>>>>>> think from where to start. I am *not* good at Image processing.
>>>>>>>>>>> Please give me some suggestions on how to start ?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>> *Cheers,*
>>>>>>>>>>> *Shivam*
>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> OWASP_PHP_Security_Project mailing list
>>>>>>>>>>> OWASP_PHP_Security_Project at lists.owasp.org
>>>>>>>>>>>
>>>>>>>>>>> https://lists.owasp.org/mailman/listinfo/owasp_php_security_project
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> OWASP_PHP_Security_Project mailing list
>>>>>>>>>> OWASP_PHP_Security_Project at lists.owasp.org
>>>>>>>>>>
>>>>>>>>>> https://lists.owasp.org/mailman/listinfo/owasp_php_security_project
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> *Cheers,*
>>>>>> *Shivam*
>>>>>>
>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> OWASP_PHP_Security_Project mailing list
>>>> OWASP_PHP_Security_Project at lists.owasp.org
>>>> https://lists.owasp.org/mailman/listinfo/owasp_php_security_project
>>>>
>>>>
>>>
>>>
>>> --
>>> Abhishek Das
>>>  IIT Roorkee
>>>
>>> _______________________________________________
>>> OWASP_PHP_Security_Project mailing list
>>> OWASP_PHP_Security_Project at lists.owasp.org
>>> https://lists.owasp.org/mailman/listinfo/owasp_php_security_project
>>>
>>>
>>
>>
>> --
>> *Cheers,*
>> *Shivam*
>>
>
>


-- 
*Cheers,*
*Shivam*
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