help needed to unpack a exe (example creakme)

[megatron]

Can anyone provide some link which has some details to unpack a creackme (Packed using UPX I think). It will be very helpful if it can  explain how the unpack of UPX works (instead of just giving steps to unpack it). I am more interested to know how it works.

[40hz]

There are several unpacking utilities available.

But what exactly are you trying to accomplish by unpacking the exe installer file as opposed to just running the executable itself?

If you're trying to circumvent a licensing or registration "wrapper," or to break some form of copy protection, or to reverse-engineer a product, then I don't think anybody here will be able to help you.

 

[scancode]

Can anyone provide some link which has some details to unpack a creackme (Packed using UPX I think). It will be very helpful if it can  explain how the unpack of UPX works (instead of just giving steps to unpack it). I am more interested to know how it works.

-megatron (January 09, 2009, 12:15 PM)

A) Crackme.
B) Where's the solution for MY crackme?

[f0dder]

As I mentioned in some other thread, DonationCoder isn't really the appropriate site for software deconstruction - even when it's legit stuff like crackmes. There's other more focused forums that'll serve you a lot better...

[megatron]

Can anyone provide some link which has some details to unpack a creackme (Packed using UPX I think). It will be very helpful if it can  explain how the unpack of UPX works (instead of just giving steps to unpack it). I am more interested to know how it works.

-megatron (January 09, 2009, 12:15 PM)

A) Crackme.
B) Where's the solution for MY crackme?

-scancode (January 09, 2009, 07:11 PM)

i am asking about the same crackme in this thread...

[scancode]

OKAY... you fail
at least you noticed the creackme thing... i was about to CREACK you

The crackme he's talking about is

Pyvpx urer vs lbh tnir hc

Gbbyf arrqrq:
ByylQOT (V hfr i1) - Funerjner (Pneqjner?)
ByylQhzc - Serr/Bcra fbhepr
Vzcbeg ERPbafgehpgbe (V hfr 1.6s ohtsvkrq) - Serrjner

--

Ybnq gur ncc va byyl.
Qb abg nanylmr.
Lbh fubhyq ynaq ba n WZC (Gevpx gb uvqr hck)
Cerff S7, lbh fubhyq ynaq ba nabgure WZC.
Xrrc cerffvat S7 'gvy lbh ynaq ng n CHFUNQ, gung'f gur orttvavat bs gur HCK hacnpxre.
Fpebyy qbja hagvy lbh frr n CBCNQ sbyybjrq ol n WZC.
Pyvpx ba gur WZC
0042489P  -R9 5OPPSQSS      WZC Cebgrpgv.004014SP
naq cerff S2 gb frg n oernxcbvag.
Cerff S9 gb eha, naq S7 gb sbyybj gur WZC.
Lbh fubhyq ynaq ng gur cebttvr'f BRC.
Cyhtvaf / ByylQhzc / Qhzc qrohttrq cebprff.
Trg RVC nf BRC, hagvpx Erohvyq Vzcbegf, jevgr qbja gur BRC, fryrpg qhzc, fnir nf QHZCRQ.RKR.
Abj, jvgubhg pybfvat byyl, bcra VzcErp.
Nggnpu gb gur penpxzr, ragre gur BRC (haqre VNG vasbf arrqrq), naq pyvpx VNG nhgb frnepu.
Pyvpx ba Trg Vzcbegf, gura ba Svk Qhzc.
Fryrpg lbhe QHZCRQ.RKR
Abj purpx gur ncc'f qverpgbel, gurer'f n arj svyr pnyyrq QHZCRQ_.RKR, naq gung'f lbhe shyyl hacnpxrq svyr.
Penpxvat gur cebgrpgvba vf yrsg nf na rkrepvfr gb gur ernqre.

_{Edit: Made it a bit harder.}

[ropt]

scancode,
i don't know if it's just me or your ZIP file is not correct. I enter in anything and it turns green all the time.

any ideas? 

[scancode]

scancode,
i don't know if it's just me or your ZIP file is not correct. I enter in anything and it turns green all the time.

any ideas? 

-ropt (January 12, 2009, 04:51 PM)

Hehehe, good job!
(Quite easy for a begginer's crackme, huh?)

[ropt]

it's easy to figure it out.

the program is made using VB6. it generates the serial using Windows Serial Number, Disk serial Number, and Network ID, then to generate a fingerprint, it does a CRC32.

the timer is set to trigger every 2 or 3 seconds. the fingerprint is 18 characters, I reduced it to [any character] as fingerprint.