rE: How to modify a 16 bit exe file

[Aziz B <Blink74@...>]

Hi


if the program you whant to protect is tiny (Less than 64Kb)
or he is tiny after you compress it using any packer, read below
if no, STOP reading this right now, and search in another message
or in other places maybe you found what you need :)

i am not a freak (a am newcomer in this scene!)
i don't know it the best but here is my best (for now)

Choise One from Three:

1 - convert your program to COM unsing any program who do it
like Ben Castricum's UNP 4.12, after that write your protection
code ( in assembly as com file) then attach your converted 16 bit
exectuble file to the end of the assembled code.
when executing your program (assembled code) will evaluate a condition
if the condition satisfied it move your converted 16 bit exe to 100h
and restor all register as default and jump to 100h
else it will display your error message and exit.
if don't understand any thing just mail me back and i will give you
a simple source file (you should send me a copy of your program!)

2 - Use my little lame protector EXOM posted to the exelist
(if you hack it, you will find the way i use...
and RiP from it ;) sorry for the word RiP, i should use the word learn :)

3 - Use the way Exe (no overwiting) virus use to infect a file
(by changing the entry point of exe file to the loaction of
the added virus, and after that he jump back to the host) try
to find in the internet a good exe virus tutoral, or read
the Giant Black Book by Mark Ludwig (a Must :)
i don't tell you to write virus, but get ideas from them
to attach a code to a program without overwriting it :)

the last one work's fine, even if your program is n't tiny :)

i just tryed to help, with my bit of knowledge.

Keep on coding 16 bit exe...

Aziz B (Blink74@...)

______________________________________________________
Boîte aux lettres - Caramail - http://www.caramail.com