Anthropic-Cybersecurity-Skills/skills/reverse-engineering-malware-with-ghidra/scripts/agent.py

#!/usr/bin/env python3
"""Malware reverse engineering agent using Ghidra headless analyzer and r2pipe."""

import subprocess
import os
import sys
import json
import re
import hashlib

try:
    import r2pipe
except ImportError:
    r2pipe = None


def compute_hashes(filepath):
    """Compute file hashes for identification."""
    with open(filepath, "rb") as f:
        data = f.read()
    return {
        "md5": hashlib.md5(data).hexdigest(),
        "sha1": hashlib.sha1(data).hexdigest(),
        "sha256": hashlib.sha256(data).hexdigest(),
        "size": len(data),
    }


def run_ghidra_headless(ghidra_path, project_dir, project_name, binary_path,
                        script=None, script_args=None):
    """Run Ghidra in headless mode for automated analysis."""
    os.makedirs(project_dir, exist_ok=True)
    cmd = [
        os.path.join(ghidra_path, "support", "analyzeHeadless"),
        project_dir, project_name,
        "-import", binary_path,
        "-overwrite",
    ]
    if script:
        cmd.extend(["-postScript", script])
        if script_args:
            cmd.extend(script_args)
    result = subprocess.run(
        cmd, capture_output=True, text=True, timeout=600
    )
    return {
        "command": " ".join(cmd),
        "returncode": result.returncode,
        "stdout": result.stdout[-2000:] if result.stdout else "",
        "stderr": result.stderr[-1000:] if result.stderr else "",
    }


def export_functions_ghidra(ghidra_path, project_dir, project_name, binary_path,
                            output_file):
    """Export function list using Ghidra headless with a script."""
    script_content = """
import ghidra.program.model.listing.FunctionIterator
import json

output = []
fm = currentProgram.getFunctionManager()
funcs = fm.getFunctions(True)
for func in funcs:
    entry = {
        "name": func.getName(),
        "address": str(func.getEntryPoint()),
        "size": func.getBody().getNumAddresses(),
        "calling_convention": func.getCallingConventionName(),
        "is_thunk": func.isThunk(),
    }
    output.append(entry)

with open("{output}", "w") as f:
    json.dump(output, f, indent=2)
""".replace("{output}", output_file.replace("\\", "\\\\"))
    script_path = os.path.join(project_dir, "export_functions.py")
    with open(script_path, "w") as f:
        f.write(script_content)
    return run_ghidra_headless(
        ghidra_path, project_dir, project_name, binary_path,
        script="export_functions.py"
    )


def analyze_with_radare2(filepath):
    """Analyze binary with radare2 via r2pipe for quick triage."""
    if r2pipe is None:
        return {"error": "r2pipe not installed (pip install r2pipe)"}
    r2 = r2pipe.open(filepath, flags=["-2"])
    r2.cmd("aaa")
    info = r2.cmdj("ij")
    functions = r2.cmdj("aflj") or []
    imports = r2.cmdj("iij") or []
    strings = r2.cmdj("izj") or []
    sections = r2.cmdj("iSj") or []
    entry_points = r2.cmdj("iej") or []
    suspicious_imports = {
        "injection": ["VirtualAllocEx", "WriteProcessMemory", "CreateRemoteThread",
                      "NtCreateThreadEx"],
        "network": ["InternetOpenA", "HttpSendRequestA", "WSAStartup",
                     "URLDownloadToFileA"],
        "evasion": ["IsDebuggerPresent", "CheckRemoteDebuggerPresent",
                     "NtQueryInformationProcess"],
        "crypto": ["CryptEncrypt", "CryptDecrypt", "CryptAcquireContextA"],
        "persistence": ["RegSetValueExA", "CreateServiceA"],
    }
    import_findings = []
    for imp in imports:
        name = imp.get("name", "")
        for category, funcs in suspicious_imports.items():
            if name in funcs:
                import_findings.append({
                    "category": category,
                    "function": name,
                    "library": imp.get("lib", ""),
                })
    network_strings = []
    for s in strings:
        val = s.get("string", "")
        if re.search(r"https?://", val) or re.search(r"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b", val):
            network_strings.append(val[:200])
    section_analysis = []
    for sec in sections:
        entropy = sec.get("entropy", 0)
        flags = []
        if entropy and entropy > 7.0:
            flags.append("HIGH_ENTROPY")
        section_analysis.append({
            "name": sec.get("name", ""),
            "size": sec.get("size", 0),
            "vsize": sec.get("vsize", 0),
            "entropy": entropy,
            "flags": flags,
        })
    r2.quit()
    return {
        "info": {
            "arch": info.get("bin", {}).get("arch", ""),
            "bits": info.get("bin", {}).get("bits", 0),
            "os": info.get("bin", {}).get("os", ""),
            "type": info.get("bin", {}).get("bintype", ""),
            "compiler": info.get("bin", {}).get("compiler", ""),
        },
        "function_count": len(functions),
        "import_count": len(imports),
        "string_count": len(strings),
        "suspicious_imports": import_findings,
        "network_indicators": network_strings[:20],
        "sections": section_analysis,
        "entry_points": [{"vaddr": e.get("vaddr"), "type": e.get("type")} for e in entry_points],
    }


def extract_crypto_constants(filepath):
    """Search binary for known cryptographic constants."""
    with open(filepath, "rb") as f:
        data = f.read()
    constants = {
        "AES_SBOX": bytes([0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5]),
        "RC4_INIT": bytes(range(256)),
        "SHA256_INIT": bytes.fromhex("6a09e667bb67ae853c6ef372a54ff53a"),
        "RSA_MAGIC": b"RSA1",
    }
    found = []
    for name, pattern in constants.items():
        offset = data.find(pattern)
        if offset >= 0:
            found.append({"constant": name, "offset": hex(offset)})
    return found


def analyze_malware(filepath, ghidra_path=None, output_dir="/tmp/ghidra_analysis"):
    """Full malware analysis pipeline."""
    os.makedirs(output_dir, exist_ok=True)
    report = {"file": os.path.basename(filepath)}
    report["hashes"] = compute_hashes(filepath)
    report["crypto_constants"] = extract_crypto_constants(filepath)
    if r2pipe:
        report["radare2"] = analyze_with_radare2(filepath)
    if ghidra_path and os.path.exists(ghidra_path):
        ghidra_result = run_ghidra_headless(
            ghidra_path, output_dir, "malware_project", filepath
        )
        report["ghidra"] = {
            "analysis_complete": ghidra_result["returncode"] == 0,
            "output": ghidra_result["stdout"][-500:],
        }
    return report


def print_report(report):
    print("Malware Reverse Engineering Report")
    print("=" * 50)
    print(f"File: {report['file']}")
    print(f"SHA-256: {report['hashes']['sha256']}")
    print(f"Size: {report['hashes']['size']} bytes")
    if report.get("crypto_constants"):
        print(f"\nCrypto Constants Found:")
        for c in report["crypto_constants"]:
            print(f"  {c['constant']} at {c['offset']}")
    r2 = report.get("radare2", {})
    if r2 and "error" not in r2:
        info = r2.get("info", {})
        print(f"\nBinary Info: {info.get('arch', '?')}/{info.get('bits', '?')}bit "
              f"({info.get('os', '?')}) [{info.get('type', '?')}]")
        print(f"Functions: {r2.get('function_count', 0)}")
        print(f"Imports: {r2.get('import_count', 0)}")
        if r2.get("suspicious_imports"):
            print(f"\nSuspicious Imports:")
            for imp in r2["suspicious_imports"]:
                print(f"  [{imp['category']}] {imp['library']} -> {imp['function']}")
        if r2.get("network_indicators"):
            print(f"\nNetwork Indicators:")
            for ni in r2["network_indicators"][:10]:
                print(f"  {ni}")
        print(f"\nSections:")
        for sec in r2.get("sections", []):
            flags = f" [{', '.join(sec['flags'])}]" if sec.get("flags") else ""
            print(f"  {sec['name']:10s} size={sec['size']:>8} entropy={sec.get('entropy', 0):.2f}{flags}")
    if report.get("ghidra", {}).get("analysis_complete"):
        print(f"\nGhidra: Analysis complete")


if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: python agent.py <binary> [ghidra_install_path]")
        sys.exit(1)
    binary = sys.argv[1]
    ghidra = sys.argv[2] if len(sys.argv) > 2 else None
    result = analyze_malware(binary, ghidra_path=ghidra)
    print_report(result)