Xigncode Blockage Error

Ok... Can someone explain this to me in very easy detail?

You know when a hack is block on SANA, we say, "Oh, Xigncode has blocked it"

HOW does it block it? Can someone tell me an code-ic way how Xigncode/Gameguard block's hacks?

I just want an in-deph detail. But please, explain simple as possible

Gameguard is not used here.

Here's some info I've gathered overtime.
Xigncode.log uses CheckDebuggerPresent and IsDebuggerPresent to check if any debuggers are being used.
xxd.xem runs in game, probably scanning for memory edits, etc.
xsg32.exe and xm.exe show the error of application once hack is detected.
Rather there's xigncode within suddenattack.exe, i don't know. But this should be give you some knowledge you didn't have before.