Target by TDC
A gui-based crackme written in visual studio 2017 win32 api, which creates a serial key based on user name.
Objectives:
- Remove the starting Nag Screen
- When the button Re-Check is clicked, a pop-up messagebox appears and you should set it to say “Thank you for registering this software”
- Set the Status box text to: “Clean crack! Good Job!”
Link: https://crackinglessons.com/6-target-by-tdc/
Software
It was a software where it show NAG at the beginning then checks for the registration status.
Detect It Easy (die)
Using DIE software I found the entry point.
EntryPoint = ImageBase + AddressOfEntryPoint --> 0x00401000
x32dbg
I opened x32dbg and found the point using intermodular calls method.
It was executing a cmp command and according to its output it executes JE (JZ) or not.
So I updated it to JMP to a point where there is no NAG command.
Then continued debugging and found the location where comparisons about recheck button is executed.
Updated it too, to bypass registration.
And we both bypassed NAG and registered.