"""Extract Agent Tesla RAT configuration from .NET assemblies."""
import re
import sys
import json
import base64
import hashlib
from pathlib import Path
def extract_strings_from_dotnet(filepath):
"""Extract readable strings from .NET binary for config analysis."""
with open(filepath, 'rb') as f:
data = f.read()
strings = []
patterns = {
"smtp_server": re.compile(rb'smtp[\.\-][\w\.\-]+\.\w{2,}', re.I),
"email": re.compile(rb'[\w\.\-]+@[\w\.\-]+\.\w{2,}'),
"ftp_url": re.compile(rb'ftp://[\w\.\-:/]+', re.I),
"telegram_token": re.compile(rb'\d{8,10}:[A-Za-z0-9_-]{35}'),
"telegram_chat": re.compile(rb'(?:chat_id=|chatid[=:])[\-]?\d{5,15}', re.I),
"discord_webhook": re.compile(rb'https://discord\.com/api/webhooks/\d+/[\w-]+'),
"password": re.compile(rb'(?:pass(?:word)?|pwd)[=:]\s*[\w!@#$%^&*]{4,}', re.I),
"port": re.compile(rb'(?:port|smtp_port)[=:]\s*\d{2,5}', re.I),
}
results = {}
for name, pattern in patterns.items():
matches = pattern.findall(data)
if matches:
results[name] = [m.decode('utf-8', errors='replace') for m in matches]
b64_pattern = re.compile(rb'[A-Za-z0-9+/]{20,}={0,2}')
b64_decoded = []
for match in b64_pattern.finditer(data):
try:
decoded = base64.b64decode(match.group())
text = decoded.decode('utf-8', errors='strict')
if text.isprintable() and len(text) > 5:
b64_decoded.append(text)
except Exception:
pass
if b64_decoded:
results["base64_decoded_strings"] = b64_decoded[:30]
return results
def decrypt_agenttesla_strings(data, key_hex):
"""Decrypt Agent Tesla encrypted configuration strings."""
key = bytes.fromhex(key_hex)
decrypted_strings = []
blob_pattern = re.compile(rb'[\x80-\xff]{16,256}')
for match in blob_pattern.finditer(data):
blob = match.group()
decrypted = bytes(b ^ key[i % len(key)] for i, b in enumerate(blob))
try:
text = decrypted.decode('utf-8', errors='strict')
if text.isprintable() and len(text.strip()) > 3:
decrypted_strings.append(text.strip())
except UnicodeDecodeError:
pass
sha256_key = hashlib.sha256(key).digest()
return decrypted_strings
def analyze_exfiltration_config(config):
"""Analyze extracted configuration for exfiltration methods."""
methods = []
if config.get("smtp_server"):
methods.append({
"type": "SMTP",
"servers": config["smtp_server"],
"emails": config.get("email", []),
})
if config.get("ftp_url"):
methods.append({
"type": "FTP",
"urls": config["ftp_url"],
})
if config.get("telegram_token"):
methods.append({
"type": "Telegram",
"tokens": config["telegram_token"],
"chat_ids": config.get("telegram_chat", []),
})
if config.get("discord_webhook"):
methods.append({
"type": "Discord",
"webhooks": config["discord_webhook"],
})
return methods
if __name__ == "__main__":
if len(sys.argv) < 2:
print(f"Usage: {sys.argv[0]} <agent_tesla_sample>")
sys.exit(1)
config = extract_strings_from_dotnet(sys.argv[1])
methods = analyze_exfiltration_config(config)
report = {"raw_config": config, "exfiltration_methods": methods}
print(json.dumps(report, indent=2))
