Performing Automated Malware Analysis With Cape

Performing Automated Malware Analysis with CAPE

Overview

CAPE (Config And Payload Extraction) is an open-source malware sandbox derived from Cuckoo that automates behavioral analysis, payload dumping, and configuration extraction. CAPEv2 features API hooking for behavioral instrumentation, captures files created/modified/deleted during execution, records network traffic in PCAP format, and includes 70+ custom configuration extractors (cape-parsers) for families like Emotet, TrickBot, Cobalt Strike, AsyncRAT, and Rhadamanthys. The signature system includes 1000+ behavioral signatures detecting evasion techniques, persistence, credential theft, and ransomware behavior. CAPE's debugger enables dynamic anti-evasion bypasses combining debugger actions within YARA signatures. Recommended deployment: Ubuntu LTS host with Windows 10 21H2 guest VM.

When to Use

Trigger phrases:

• "performing automated malware analysis with cape"

• "Deploy and operate CAPEv2 sandbox for automated malware analysis with behavioral"

• When conducting security assessments that involve performing automated malware analysis with cape

• When following incident response procedures for related security events

• When performing scheduled security testing or auditing activities

• When validating security controls through hands-on testing

Prerequisites

• Ubuntu 22.04 LTS server (8+ CPU cores, 32GB+ RAM, 500GB+ SSD)
• KVM/QEMU virtualization support
• Windows 10 21H2 guest image
• Python 3.9+ with CAPEv2 dependencies
• Network configuration for isolated analysis network

Workflow

1. Isolate the sample — ensure the malware is in a sandboxed environment with no network access
2. Record file metadata — hash the sample and note file type, size, and compile timestamp
3. Static analysis — examine strings, imports, and disassembled code without execution
4. Dynamic analysis — execute in a monitored sandbox and record behavior (file, registry, network)
5. Document IOCs — extract indicators of compromise and write the analysis report

Step 1: Submit and Analyze Samples via API

#!/usr/bin/env python3
"""CAPE sandbox API client for automated malware submission and analysis."""
import requests
import json
import time
import sys
from pathlib import Path


class CAPEClient:
    def __init__(self, base_url="http://localhost:8000", api_token=None):
        self.base_url = base_url.rstrip("/")
        self.headers = {}
        if api_token:
            self.headers["Authorization"] = f"Token {api_token}"

    def submit_file(self, filepath, options=None):
        """Submit a file for analysis."""
        url = f"{self.base_url}/apiv2/tasks/create/file/"
        files = {"file": open(filepath, "rb")}
        data = options or {}
        data.setdefault("timeout", 120)
        data.setdefault("enforce_timeout", False)

        resp = requests.post(url, files=files, data=data, headers=self.headers)
        resp.raise_for_status()
        result = resp.json()
        task_id = result.get("data", {}).get("task_ids", [None])[0]
        print(f"[+] Submitted {filepath} -> Task ID: {task_id}")
        return task_id

    def get_status(self, task_id):
        """Check task analysis status."""
        url = f"{self.base_url}/apiv2/tasks/status/{task_id}/"
        resp = requests.get(url, headers=self.headers)
        return resp.json().get("data", "unknown")

    def wait_for_completion(self, task_id, poll_interval=15, max_wait=600):
        """Wait for analysis to complete."""
        elapsed = 0
        while elapsed < max_wait:
            status = self.get_status(task_id)
            if status == "reported":
                print(f"[+] Task {task_id} completed")
                return True
            time.sleep(poll_interval)
            elapsed += poll_interval
            print(f"  Waiting... ({elapsed}s, status: {status})")
        return False

    def get_report(self, task_id):
        """Retrieve full analysis report."""
        url = f"{self.base_url}/apiv2/tasks/get/report/{task_id}/"
        resp = requests.get(url, headers=self.headers)
        return resp.json()

    def get_config(self, task_id):
        """Get extracted malware configuration."""
        report = self.get_report(task_id)
        configs = report.get("CAPE", {}).get("configs", [])
        return configs

    def get_dropped_files(self, task_id):
        """List files dropped during analysis."""
        report = self.get_report(task_id)
        return report.get("dropped", [])

    def get_network_iocs(self, task_id):
        """Extract network IOCs from analysis."""
        report = self.get_report(task_id)
        network = report.get("network", {})
        iocs = {
            "dns": [d.get("request") for d in network.get("dns", [])],
            "http": [h.get("uri") for h in network.get("http", [])],
            "tcp": [f"{h.get('dst')}:{h.get('dport')}"
                    for h in network.get("tcp", [])],
        }
        return iocs

    def analyze_sample(self, filepath):
        """Full automated analysis pipeline."""
        task_id = self.submit_file(filepath)
        if not task_id:
            return None

        if self.wait_for_completion(task_id):
            report = {
                "task_id": task_id,
                "config": self.get_config(task_id),
                "network_iocs": self.get_network_iocs(task_id),
                "dropped_files": len(self.get_dropped_files(task_id)),
            }
            return report
        return None


if __name__ == "__main__":
    if len(sys.argv) < 2:
        print(f"Usage: {sys.argv[0]} <malware_sample> [cape_url]")
        sys.exit(1)

    url = sys.argv[2] if len(sys.argv) > 2 else "http://localhost:8000"
    client = CAPEClient(url)
    result = client.analyze_sample(sys.argv[1])
    if result:
        print(json.dumps(result, indent=2))

Validation Criteria

• Samples submitted and analyzed within configured timeout
• Behavioral signatures triggered for known malware families
• Malware configurations extracted by cape-parsers
• Network traffic captured and IOCs extracted
• Dropped files and payloads collected for further analysis
• Anti-evasion bypasses effective against sandbox-aware malware

When NOT to Use

• You don't have explicit written authorization to test
• Task is about defense/detection, not offense (use detection skills)
• You need to implement security controls (use implementing-* skills)
• Task requires compliance auditing (use auditing-* skills)
• You're investigating an incident (use incident response skills)
• Target is out of scope for your engagement
• Task is about vulnerability scanning only (use scanning tools)

Red Flags

• Performing actions without explicit written authorization from the asset owner
• Testing against production systems without a defined scope and rules of engagement
• Analyzing malware on a machine connected to the production network
• Failing to isolate the analysis environment from the internet
• Executing samples without proper containment (VM, sandbox)

Verification

• All steps executed successfully against a test environment before production use
• Output documented with screenshots or logs demonstrating expected behavior
• Sample hash recorded and verified (MD5, SHA-1, SHA-256)
• Analysis environment confirmed isolated from production network
• Indicators of compromise (IOCs) extracted and documented

References

• CAPEv2 GitHub
• CAPE Sandbox Documentation
• Automating Malware Analysis with CAPE
• Installing CAPEv2 on Ubuntu

Process

1. Analyze the task requirements
2. Apply domain expertise
3. Verify output quality

Anti-Rationalization Table