World's smallest Windows program

[Gigasoft]

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.

[ru2aqare]

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.

[Gigasoft]

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.

[Owen]

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

[Combuster]

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.

[VolTeK]

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

[Gigasoft]

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

[redoktober]

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?

[qw]

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).

[Gigasoft]

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

[qw]

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.

[redoktober]

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