Bit of Forensics


I like using dcfldd for creating the raw images, because it shows a nice status…it’s interesting to see progress.

dcfldd if=/dev/sda of=/mnt/sdb1/filename.dd hash=md5 md5log=hashfile.md5 conv=noerror,sync bs=4096

It’s the ‘bs’ (stands for bytesize) that makes the difference (…always does doesn’t it ;-).

Autopsy – The forensics browser always uses the ~/.autopsy as the base directory for storing the files from the cases. The following command is helpful in changing the directory in which the cases should be stored:

./autopsy -d /mountpoint/dirname

The exiftool is a cool application that can read meta-information to determine the different types of files.


The first interview of my life


This is not a post but nostalgia. This post is actually a transcript of the first interview of my life. It was for a top Indian Software Consultancy Company (referred to as “XYZ” from now on). I remember that it was July 9th, 2001 and it was a really rainy day in Bombay. While coming to the college I was totally drenched and was looking rather distraught! I cleared the aptitude test and then came the Big One – The Interview!
I went to the interview thinking that i wanted to completely screw up the interview (coz I was interested in some other company) so i went there casually dressed with a demonic smile on my face >:-) . In hindsight, I think the way I appeared for this interview was really gutsy for me and I probably couldn’t have done that had I been craving to get a job in this company. Here is the transcript of the interview.

XYZ: So Mr Rajat … tell me about urself and ur family in *short*
Me : In the year 1980 i was born in allahabad and spent the initial yrs of mylife in blah blah blah ….and completed my schooling in Shree Ram Welfare Society’s High School, Andheri(W), Mumbai . therafter i went to Sathaye College….(blah blah blah) and i came to this college thinking that this college would be good.
XYZ: & how did u find this college?
Me : (thinkin for a while and then with a heavy heart ) ok !
XYZ: Rajat y did u chose our company (XYZ) instead of other companies.
Me : i did not choose XYZ i’ve just come for this interview ! In fact u guys have come to our college (for on-campus placements) i haven’t come for this interview.
XYZ: but would u like to join our co.?
Me: i’ve come for this interview ! what does this indicate to u?
XYZ: give me one reason why u want to join XYZ?
Me: i don’t want join XYZ… i’ll goto any other co. that comes next…as a matter of fact any other co. will take me!
XYZ: Mr Rajat in this form (these guys had given us a form to fill in whichwe were supposed to write the salary we desired which i forgot to fill… oops faux pas ? well not quite) which we have given to u , uhaven’t mentioned the salary u want…. what r ur expectations?
Me : I want more!
XYZ: MORE !%#$%$#$ y do u want more?
Me: because i know i’m worth it!
XYZ: u say so but it is for us to see whether u r worth it!
Me: put me to test and i’ll prove i’m worth it !
XYZ: but why do u want more ?
Me : everybody wants more so what is wrong if i want more!(the guy seems to be pissed off to my delight)
XYZ: but u must be having some expectations , don’t u?
Me : yes of course , i have . but u r not gonna live up to them. u had made it quite clear the salary u’ll be offering to us … so it doesn’t matter what my expectations are u r gonna give only what *you* want to give us , so there rests the matter.
XYZ: tell me about this person whom u know & works in XYZ.
Me : He is my cousin and he stays at andheri.
XYZ: so what have u heard from him about our co. ?
XYZ: but u might have heard something at least!!!!!
ME : we meet at social gatherings and the last thing we want to speak about is XYZ!!!
XYZ: ok tell me about ur project … this assembler
Me : blah blah blah
XYZ: ok … so in ur form u write u want “A GOOD NETWORKING PROJECT PREFERABLY BASED ON NETWORK SECURITY” . what do u know about networking?
XYZ: (a very surprised Mr. Sleepy said) NOTHING !?!? then how can u say u want a project in it?
Me: well , i’ve attended a few seminars @ IIT and it ensured me that that was the only field i’m interested in.
XYZ: then ur interest may change after studying the subject!
Me : No, it won’t change!!!!
XYZ: wat do u know bout networkin?
Me: latest happenings … blah blah blah
XYZ: suppose that we don’t have a project in network securities for you then what will u do?
Me: i have written that it is my ambition to work on a networking project…AMBITIONS ARE NOT ALWAYS FULFILLED.
XYZ: Rajat … there is a rule in ur college that if u get 1 co. u r noteligible for the rest.we offer u 16k .. so if tomorrow infosys comes and offers u 20k wat will u do?
Me : I WILL GO !!!!!
XYZ: u’ll go !?! that means you are after money ?
Me : who said that !? i never said that ! i want more money but more important than that is the work environment & the kind of projects i get. if i getbetter projects there i’ll go money is secondary but still important .
XYZ: (as if trying to juistify a lesser salary) u know rajat that on paper their (Infosys) salary may look large but 20% blah blah blah ….. 12.5 % blahblah blah …6% blah blah blah … (and lots more statistics which lasted foran eternity as far as my viewpoint goes)
XYZ: do u realise that XYZ has a 3yr. service agreement or u r chargedRs.50,000/- . what are your feelings about that?
Me : it is absolutely wrong.
XYZ: why?
Me: The word “bond” itself says that u r “bound” to the co. no matter what.
XYZ: that is why we don’t call it a “bond” we call it a “service agreement”.
Me: ok…that’s just another name for it. i personally think that instead of”binding” people to ur co. u should create such an environment that people like to stay in ur co. with their wishes and so the co. will benefit if peoplework with their wishes.
XYZ: do u havre any questions for us?
Me: yes , sir i do! in ur qns a few minutes back u mentioned infosys and in ur pre-placement talks u said u r no.1 software co. of india. how can u say thatwhen all that we see in the newspapers is infosys and with u comparing urself to infosys?
XYZ: infosys is 12% blah blah blah … 19% blah blah blah …(and lots morestatistics that made me feel as miserable as our indian cricket team witheverything out of control)does that answer ur qn?
Me: ya! sir may i ask another question ?
XYZ: ya sure! (with some uneasiness)
Me: sir, this yr. we have seen our seniors get whole lot of “back out” letters! what r ur feelings about that?
Me: i mean r u people going to do the same with us?
XYZ: (i think this was it and he lost his complete cool and he pointed to me & said sternly) till this date our company has not given any “back-out” letters to anybody.
Me: Thank u .sir. it was a pleasure!

This was the first interview of my life and I ended up getting selected for this company. It was a great experience working there and I realized that money is not everything! At the end of it I think I was not rude but dangerously honest in giving my answers and this plan could have backfired on me but it didn’t … may be I was lucky or may be this was destiny!


A disaster called Silsilay


Silsilay, the latest movie by Khalid Mohammed, a critic famous for his Sunday Times articles, is a disaster to say the least. Mr.Mohammed, who has torn apart most of the movies in his journalism career, to my disappointment, has not proven himself any better than the pack he tore apart. I think if he himself saw the movie impartially he probably would have given it negative five stars.
Silsilay, as the movie is called, is a movie of three stories running one after the other albeit aimlessly. The first story is of a film actress (Bhoomika Chawla) who falls in love with a bookie (Rahul Bose) who is two-timing his girl-friend, who in turn is two-timing him…sounds complex…don’t bother…it’s not complex but just kiwi drainex!
The second story is of a young girl (Riya Sen) who looks stunning in the movie and is afraid to lose her virginity and is consoled by her overly promiscuous friend to do *it*. Ashmit Patel steps into the story as her boy toy (read “snuggies”) and Jimmy Shergill, who is her co-worker from work and is looking to gain her attention. Some good (aimless) smooches result between Ashmit and Riya and Khalid Mohammed succeeds in spinning a story that is as ridiculous as Riya and Ashmit’s acting. For god’s sake Riya, Nirma soap advertisements were better!
As if the torture was not enough, Mr.Mohammed had a life-saver (or at least as he thought) a still more ridiculous story. Well, some B-grade films would have called this 3rd story a *saga*…but I frankly think that Khalid Mohammed doesn’t think!
It’s a combination of a love triangle…sorry…love quadrilateral with a diagonal (please figure out what this means on your own…watching the movie wouldn’t help anyway). In this story Tabu plays a housewife whose husband (KK) is going out with a (super hot) air hostess (Celina Jaitley) and whose son suffers from Oedipus Complex ( where a person falls in love with his own mother). As if this carcass did not stink the theatres…there was more bull**** coming across in the form of Shah Rukh Khan in between stories and scenes. Mr. Khan there are many ways to win Filmfare awards…this is probably the last way to *buy* the awards. Mr.Khan does a saving act by signalling to the audience how he behaves when nature calls arrive…how he insanely goes about dancing for no reason whatsoever.
This is all a part of the crap that I call Silsilay!
Awesome Japanese Artifacts!


Cygwin: Ambiguous redirect


An interesting thing happened today …I was trying to redirect some input to /dev/null in cygwin…using something like:
some_exec -p params 2>&/dev/null | grep blah
I kept getting an error : bash: Ambiguous redirect.
I then realized that I should probably doing a simple direct and not a re-direct…seemed to solve my problem. Come to think of it…it makes sense, why should I need to redirect when I’m sending it to /dev/null…should simply be able to direct it using:
some_exec -p paraa 2>/dev/null | grep blah


Sharing 3G connection using 802.11 Access Point


Let’s assess the situation: You have a 3G phone which allows tethering, a windows machine, a wireless access point and another PC that is connected to the LAN port of the wireless access point (or typically called a wireless router). The wireless access point is a home network and your ISP decides to disconnect your signal or is experiencing some problems. How do you share your 3G connection, so that other computers can connect through the wireless AP and use your cell phone’s 3G connection? It’s actually quite simple.

Tether your smartphone (in this case let’s say blackberry). Blackberry tethering in Windows over AT&T is allowed using a software called AT&T Communication Manager. Install ACM, and connect your Windows machine using a mini-USB cable to your phone. Goto Start->Run->cmd.exe. Type ipconfig /all to see the IP address and the DNS servers IP addresses.

Now connect the WAN link of your Wireless access point to this Windows machine’s ethernet port. Setup a static IP for this Windows machine say with a netmask of Now go to Network connections (from Control Panel), right click on the Mobile connection representing your blackberry, click on Advanced. In the Internet Connection Sharing section, check the box that says “Allow other network users to connect through this computer’s Internet connection” and select “Local Area Connection” (this is the same connection you connected to the WAN port of the wireless AP). Click OK. You may have to disconnect and reconnect your ACM connection to allow the settings to take effect.

Now that this is done, connect to the administration interface of the wireless access point to the other PC that is connected to the LAN port (or through the wireless) to the access point. Go to the administration interface of the wireless AP, and set a static IP for the router in the same subnet as with the Windows box (the one you set with Set the static IP on the AP to be say (remember this has to be the same subnet), netmask as and then the most important, the default gateway to (the IP of the windows box on the ethernet card). To set the DNS server addresses, use the same addresses you found using ipconfig /all in the first step. Otherwise you could also use open DNS servers or any other DNS servers but it’ll be best to use the DNS servers pointing to the ones used by the tethered connection because you can rule out DNS issues if something isn’t working and it comes down to troubleshooting. Once on the router, the static is set, the gateway is set, the DNS is set, you should be able to connect from your wireless network to the internet through your 3G connection! 🙂
Happy internet sharing! 🙂
Here is a schematic diagram:

[tethering]                [static IP]    [static IP]   [internal IP]  [DHCP address]
                                   |         |                |           |
[ phone ] <==> [Windows machine]:eth0 <==> wan:[Wireless AP]:lan <==> [client]

BackTrack4 R2 iwlagn error


i updated my backtrack 4 R1 finally using the directions mentioned here. However, after the upgrade my Intel Corporation Wireless WiFi Link 5100 wireless adapter stopped working. My first thought was that the driver was corrupted or something after the upgrade.
But looking through the ‘dmesg‘ command output it became clear that during the startup a particular file iwlwifi-5000-2.ucode could not be located. I thought a reinstall will do it (always works right?).
# apt-get install firmware-iwlwifi
No luck yet! Searching for these files showed me that they were in two locations and both of these were identical (verified via md5sum) :

So I just added a symbolic link as follows:
ln -s /lib/firmware-2.6.34/iwlwifi-5000-2.ucode /lib/firmware-
Voila! It now worked! Hope it helps!


Kubuntu Static IP Script


I wrote a very small script to set static IPs on a kubuntu box.

if [ $# -lt 4 ]
    echo "Usage: $0 <interface> <ip> <netmask> <gateway> <dns1>"
ifconfig $1 $2 netmask $3
echo "Static IP set"
route add default gw $4
echo "Routes added"
if [ "$5" != "" ]
    echo "nameserver $5" >>/etc/resolv.conf
echo "DNS set"