Cheat Engine

[MichaelLee01]

hello I created a Xp hack,I used to set xp to a specific value using mov.

but now I want to write a Triple xp hack,but no matter how i try ,the game crashed

Here is the script:
{ Game : FSD-Win64-Shipping.exe
Version:
Date : 2020-04-19
Author : Administrator

This script does blah blah blah
}

[ENABLE]

aobscanmodule(Exp,FSD-Win64-Shipping.exe,FF 80 38 03 00 00) // should be unique
alloc(newmem,$1000,FSD-Win64-Shipping.exe+66A2ED)

label(return)
//label(multiply)

newmem:
//inc [rax+00000338]//this is the original code
push rbx
mov rbx,#3
mul rbx
mov [rax+00000338],rbx
pop rbx
jmp return


Exp:
jmp newmem
nop
return:
registersymbol(Exp)

[DISABLE]

Exp:
db FF 80 38 03 00 00

unregistersymbol(Exp)
dealloc(newmem)

{
// ORIGINAL CODE - INJECTION POINT: FSD-Win64-Shipping.exe+66A5BB

"FSD-Win64-Shipping.exe"+66A594: 48 8B 40 30 - mov rax,[rax+30]
"FSD-Win64-Shipping.exe"+66A598: FF 50 10 - call qword ptr [rax+10]
"FSD-Win64-Shipping.exe"+66A59B: 48 8D 54 24 30 - lea rdx,[rsp+30]
"FSD-Win64-Shipping.exe"+66A5A0: 49 8B CD - mov rcx,r13
"FSD-Win64-Shipping.exe"+66A5A3: 0F 10 00 - movups xmm0,[rax]
"FSD-Win64-Shipping.exe"+66A5A6: 0F 29 44 24 30 - movaps [rsp+30],xmm0
"FSD-Win64-Shipping.exe"+66A5AB: E8 30 6D 04 00 - call FSD-Win64-Shipping.exe+6B12E0
"FSD-Win64-Shipping.exe"+66A5B0: 49 8B CC - mov rcx,r12
"FSD-Win64-Shipping.exe"+66A5B3: E8 78 BE 03 00 - call FSD-Win64-Shipping.exe+6A6430
"FSD-Win64-Shipping.exe"+66A5B8: 48 8B CE - mov rcx,rsi
// ---------- INJECTING HERE ----------
"FSD-Win64-Shipping.exe"+66A5BB: FF 80 38 03 00 00 - inc [rax+00000338]
// ---------- DONE INJECTING ----------
"FSD-Win64-Shipping.exe"+66A5C1: 48 8B 06 - mov rax,[rsi]
"FSD-Win64-Shipping.exe"+66A5C4: FF 50 10 - call qword ptr [rax+10]
"FSD-Win64-Shipping.exe"+66A5C7: 48 8D 15 F2 36 EE 02 - lea rdx,[FSD-Win64-Shipping.exe+354DCC0]
"FSD-Win64-Shipping.exe"+66A5CE: 48 89 7D 9F - mov [rbp-61],rdi
"FSD-Win64-Shipping.exe"+66A5D2: 48 8D 4D 9F - lea rcx,[rbp-61]
"FSD-Win64-Shipping.exe"+66A5D6: 48 89 7D A7 - mov [rbp-59],rdi
"FSD-Win64-Shipping.exe"+66A5DA: 48 8B D8 - mov rbx,rax
"FSD-Win64-Shipping.exe"+66A5DD: 48 89 7D AF - mov [rbp-51],rdi
"FSD-Win64-Shipping.exe"+66A5E1: 48 89 7D B7 - mov [rbp-49],rdi
"FSD-Win64-Shipping.exe"+66A5E5: E8 26 DF 0A 01 - call FSD-Win64-Shipping.exe+1718510
}

[happyTugs]

You are crashing since the product is stored in the accumulator register (not rbx).

The following links should help you figure it out yourself.

https://wiki.cheatengine.org/index.php?title=Assembler:Commands:MUL
https://stackoverflow.com/questions/40893026/mul-function-in-assembly