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PB 9 Executable: Checksum changes each compile

Started by Theo Gottwald, August 16, 2008, 09:51:34 AM

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Theo Gottwald

There is another interesting difference to PB 8, I've noticed with the new compiler:

The checksum of the executable seems to change at any compile.
Even if the source code is not beeing changed.

Means you do not need to change the source code.
Just compile it, rename the file. Compile it again, rename the file.
Do it a third time. All three files may now have a different checksum.

You can verify a checksum with a Checksumm-Tool, or just upload the file to
Virustotal. Besides the Virus Scan, it will also display some checksums of the file.

There are some bytes from position $530 - $539 in the executable which are changed during any compilation.
Do they contain info about the time of the compilation?

Actually I do not know why, at least that was not the case in PB 8 and its the case in PB 9.

Anthony Giambalvo


What I have detected is that it appears that each time you compile a new GUID is generated inside the executable.  That is the only change I can find between subsequent compiles.

Anthony Giambalvo

Edwin Knoppert

New guids should only be there if you don't set them (all)