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Active Forums => Programs => Topic started by: NOVARSEG on February 17, 2021, 08:53:43 pm

Title: Editing EXE file to swap values
Post by: NOVARSEG on February 17, 2021, 08:53:43 pm: So using a hex editor :) it is possible to find the address bytes in a QB64 EXE and swap the address of one variable with another.

This is the BAS file (complied and then edited the EXE)

It swaps A with B. Only had to change two bytes with the editor.

DIM A AS _UNSIGNED LONG
DIM B AS _UNSIGNED LONG

GOSUB LL1
PRINT A
PRINT B

END

LL1:

A = 808530224 ' look for "0110"
B = 825373233 ' look for "1221"

RETURN

**** This is for experiment only, do not adjust your set

If anyone wants the EXE then say so
Title: Re: Editing EXE file to swap values
Post by: SpriggsySpriggs on February 17, 2021, 08:54:52 pm: Look at OpenProcess on the MSDN
Title: Re: Editing EXE file to swap values
Post by: SMcNeill on February 17, 2021, 09:00:03 pm: Easy way is to just open your source and then: SWAP A, B
Title: Re: Editing EXE file to swap values
Post by: NOVARSEG on February 17, 2021, 09:25:16 pm: Yep that works too.

what the unedited bytes look like in the EXE

A1 4C 2B 6B 00 'address = 6B2B4C
C7 00 30 31 31 30 '30 31 31 30 = 808530224 dec

A1 50 2B 6B 00 'address = 6B2B50
C7 00 31 32 32 31 '31 32 32 31 = 825373233 dec

****

the edited bytes

A1 50 2B 6B 00 'address = 6B2B50
C7 00 30 31 31 30 '30 31 31 30 = 808530224 dec

A1 4C 2B 6B 00 'address = 6B2B4C
C7 00 31 32 32 31 '31 32 32 31 = 825373233 dec

notice the LONGs are 4 bytes apart so there are no spaces between.