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.
You might wanna take a little look (not in detail) of the texture modding of D3D.
I'm not sure. Since it's always there when you get a "hack detected" in game. Btw, wanna PM me how? XD
you can stop error of xigncode it's easy !! download xignation ! put it with dlls in the suddenattack files ! clik on the xingation , launch the launcher ! and hack