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I've broken the world record for the world's smallest Windows program. This program is 73 bytes long and the previous world record was 97 bytes.

Inside this zip file is a winhi73.com and a hi73fix.exe. Extract both to the same directory and run hi73fix.exe to patch winhi73.com to work with your version of Windows. Then run winhi73.com. If it works, it should display a message box with 3 OK buttons. It only works in 32 bit versions of Windows.

Gigasoft wrote:I've broken the world record for the world's smallest Windows program. This program is 73 bytes long and the previous world record was 97 bytes.

Inside this zip file is a winhi73.com and a hi73fix.exe. Extract both to the same directory and run hi73fix.exe to patch winhi73.com to work with your version of Windows. Then run winhi73.com. If it works, it should display a message box with 3 OK buttons. It only works in 32 bit versions of Windows.

I wouldn't call a program that runs in v86 mode (under NTVDM) a Windows program... Be it 73 or whatever bytes long. As I run an x64 Windows, I can't comment of whether it works or not.

Well, it manages to jump to arbitrary code in NTVDM, making a NtRaiseHardError call with it's own parameters and then going to ExitProcess. It could easily be expanded to do other things that normal Windows programs can do.

I wouldn't call it a Windows program, but it's a glorious hack

Gigasoft wrote:Well, it manages to jump to arbitrary code in NTVDM

So it is an DOS program exploiting a security hole in the real mode VM.

alright i mean wait, thats a bad thing good job?

Yeah, technically it starts out as a DOS program. It's not really a security hole, since DOS programs can already launch Windows programs. It's just an unintended way of doing things

strange.
i used your patch to fix the COM file, and when i run it, a console opens up, and then NTVDM crashes.
what could be the issue?

redoktober wrote:strange.
i used your patch to fix the COM file, and when i run it, a console opens up, and then NTVDM crashes.
what could be the issue?

Same with me (on XP SP2).

That's difficult to say. Could you upload or send me the patched COM file along with your version of NTVDM?

Gigasoft wrote:That's difficult to say. Could you upload or send me the patched COM file along with your version of NTVDM?

Here it is. NTVDM version is 5.1.2600.2180. I hope this information is enough, the file exceeds the upload limit.

i'll say this.
i looked through the MASM code...nice hack!