# Building Adversary Infrastructure Tracking System

> Use when building an automated system to track adversary infrastructure using passive DNS, certificate transparency, WHOIS data, and IP enrichment to map and monitor threat actor command-and-control networks.

- Skill: `oyi77/building-adversary-infrastructure-tracking-system` (Agent Skill)
- Install (CLI): `npx skillmds add oyi77/building-adversary-infrastructure-tracking-system`
- Raw SKILL.md: https://api.skillmd.com/api/skills/oyi77/building-adversary-infrastructure-tracking-system/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: Apache-2.0
- Author: oyi77 (https://skillmd.com/u/oyi77)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/oyi77/building-adversary-infrastructure-tracking-system

---


# Building Adversary Infrastructure Tracking System

## Overview

Adversary infrastructure tracking uses passive DNS records, certificate transparency logs, WHOIS registration data, and IP enrichment to discover, map, and monitor threat actor command-and-control (C2) networks. Attackers frequently reuse hosting providers, registrars, SSL certificates, and naming patterns across campaigns, enabling analysts to pivot from known indicators to discover new infrastructure. This skill covers building an automated tracking system that identifies infrastructure relationships, detects newly registered domains matching adversary patterns, and maintains a continuously updated map of threat actor networks.


## When to Use
**Trigger phrases:**
- "building adversary infrastructure tracking system"
- "Build an automated system to track adversary infrastructure using passive DNS, c"


- When deploying or configuring building adversary infrastructure tracking system capabilities in your environment
- When establishing security controls aligned to compliance requirements
- When building or improving security architecture for this domain
- When conducting security assessments that require this implementation

## Prerequisites

- Python 3.9+ with `requests`, `dnspython`, `python-whois`, `shodan`, `networkx` libraries
- API keys: SecurityTrails, PassiveTotal/RiskIQ, Shodan, VirusTotal
- Access to passive DNS data sources
- Understanding of DNS infrastructure, hosting, and domain registration
- Graph database (Neo4j) or NetworkX for relationship visualization

## Key Concepts

This section covers key concepts for building adversary infrastructure tracking system.

- Ensure all prerequisites are met before proceeding
- Follow the documented workflow steps in sequence
- Record results and any anomalies encountered during this phase
### Passive DNS

Passive DNS captures historical DNS resolution data, recording which domains resolved to which IPs and when. Unlike active DNS queries, passive DNS preserves historical relationships even after records change, enabling analysts to track infrastructure changes, identify shared hosting patterns, and discover related domains that resolved to the same IP addresses over time.

### Infrastructure Pivoting

Pivoting identifies related infrastructure by following connections: IP pivot (find all domains on an IP), domain pivot (find all IPs a domain resolved to), WHOIS pivot (find domains with same registrant), certificate pivot (find hosts sharing SSL certificates), and NS/MX pivot (find domains using same name servers or mail servers).

### Adversary Infrastructure Patterns

Threat actors exhibit patterns: preferred registrars (Namecheap, REG.RU, Tucows), preferred hosting (bulletproof hosting providers, cloud services), domain generation algorithms (DGA), consistent naming patterns, and certificate reuse across campaigns.

## Workflow

1. **Scope the task** — define objectives, boundaries, and success criteria
2. **Gather information** — collect all necessary data and context before proceeding
3. **Execute the core workflow** — follow the domain-specific steps methodically
4. **Validate results** — verify outputs against expected outcomes or baselines
5. **Document findings** — record results, anomalies, and recommendations
### Step 1: Passive DNS Infrastructure Discovery

```python
import requests
import json
from collections import defaultdict
from datetime import datetime

class InfrastructureTracker:
    def __init__(self, securitytrails_key=None, vt_key=None, shodan_key=None):
        self.st_key = securitytrails_key
        self.vt_key = vt_key
        self.shodan_key = shodan_key
        self.infrastructure_graph = defaultdict(lambda: {"nodes": set(), "edges": []})

    def passive_dns_lookup(self, domain):
        """Query passive DNS for domain resolution history."""
        headers = {"apikey": self.st_key}
        url = f"https://api.securitytrails.com/v1/history/{domain}/dns/a"
        resp = requests.get(url, headers=headers, timeout=30)
        if resp.status_code == 200:
            records = resp.json().get("records", [])
            history = []
            for record in records:
                for value in record.get("values", []):
                    history.append({
                        "domain": domain,
                        "ip": value.get("ip", ""),
                        "first_seen": record.get("first_seen", ""),
                        "last_seen": record.get("last_seen", ""),
                        "type": record.get("type", "a"),
                    })
            print(f"[+] Passive DNS for {domain}: {len(history)} records")
            return history
        return []

    def reverse_ip_lookup(self, ip_address):
        """Find all domains hosted on an IP address."""
        headers = {"apikey": self.st_key}
        url = f"https://api.securitytrails.com/v1/ips/nearby/{ip_address}"
        resp = requests.get(url, headers=headers, timeout=30)
        if resp.status_code == 200:
            blocks = resp.json().get("blocks", [])
            domains = []
            for block in blocks:
                for site in block.get("sites", []):
                    domains.append(site)
            print(f"[+] Reverse IP for {ip_address}: {len(domains)} domains")
            return domains
        return []

    def whois_lookup(self, domain):
        """Get WHOIS registration data for pivoting."""
        headers = {"apikey": self.st_key}
        url = f"https://api.securitytrails.com/v1/domain/{domain}/whois"
        resp = requests.get(url, headers=headers, timeout=30)
        if resp.status_code == 200:
            data = resp.json()
            whois_data = {
                "domain": domain,
                "registrar": data.get("registrar", ""),
                "registrant_org": data.get("registrant_org", ""),
                "registrant_email": data.get("registrant_email", ""),
                "name_servers": data.get("nameServers", []),
                "created_date": data.get("createdDate", ""),
                "updated_date": data.get("updatedDate", ""),
                "expires_date": data.get("expiresDate", ""),
            }
            return whois_data
        return {}

    def pivot_from_seed(self, seed_indicator, indicator_type="domain", depth=2):
        """Recursively pivot from a seed indicator to discover infrastructure."""
        discovered = {"domains": set(), "ips": set(), "relationships": []}

        if indicator_type == "domain":
            discovered["domains"].add(seed_indicator)
            # Get IPs for domain
            pdns = self.passive_dns_lookup(seed_indicator)
            for record in pdns:
                ip = record["ip"]
                discovered["ips"].add(ip)
                discovered["relationships"].append({
                    "source": seed_indicator, "target": ip,
                    "type": "resolves_to",
                    "first_seen": record["first_seen"],
                    "last_seen": record["last_seen"],
                })

                if depth > 1:
                    # Reverse lookup on discovered IPs
                    reverse_domains = self.reverse_ip_lookup(ip)
                    for rd in reverse_domains[:20]:
                        discovered["domains"].add(rd)
                        discovered["relationships"].append({
                            "source": rd, "target": ip,
                            "type": "hosted_on",
                        })

        elif indicator_type == "ip":
            discovered["ips"].add(seed_indicator)
            domains = self.reverse_ip_lookup(seed_indicator)
            for domain in domains[:20]:
                discovered["domains"].add(domain)
                discovered["relationships"].append({
                    "source": domain, "target": seed_indicator,
                    "type": "hosted_on",
                })

        print(f"[+] Pivot from {seed_indicator}: "
              f"{len(discovered['domains'])} domains, "
              f"{len(discovered['ips'])} IPs, "
              f"{len(discovered['relationships'])} relationships")
        return discovered

tracker = InfrastructureTracker(
    securitytrails_key="YOUR_ST_KEY",
    vt_key="YOUR_VT_KEY",
)
```

### Step 2: Build Infrastructure Graph

```python
import networkx as nx

class InfrastructureGraph:
    def __init__(self):
        self.graph = nx.Graph()

    def add_discovery(self, discovery_data):
        """Add discovered infrastructure to graph."""
        for domain in discovery_data["domains"]:
            self.graph.add_node(domain, type="domain")
        for ip in discovery_data["ips"]:
            self.graph.add_node(ip, type="ip")
        for rel in discovery_data["relationships"]:
            self.graph.add_edge(
                rel["source"], rel["target"],
                relationship=rel["type"],
                first_seen=rel.get("first_seen", ""),
                last_seen=rel.get("last_seen", ""),
            )

    def find_clusters(self):
        """Identify infrastructure clusters."""
        components = list(nx.connected_components(self.graph))
        clusters = []
        for component in components:
            domains = [n for n in component if self.graph.nodes[n].get("type") == "domain"]
            ips = [n for n in component if self.graph.nodes[n].get("type") == "ip"]
            clusters.append({
                "size": len(component),
                "domains": sorted(domains),
                "ips": sorted(ips),
                "domain_count": len(domains),
                "ip_count": len(ips),
            })
        clusters.sort(key=lambda x: x["size"], reverse=True)
        print(f"[+] Infrastructure clusters: {len(clusters)}")
        return clusters

    def find_hub_nodes(self, top_n=10):
        """Find high-centrality nodes (shared infrastructure)."""
        centrality = nx.degree_centrality(self.graph)
        top_nodes = sorted(centrality.items(), key=lambda x: x[1], reverse=True)[:top_n]
        hubs = []
        for node, score in top_nodes:
            hubs.append({
                "node": node,
                "type": self.graph.nodes[node].get("type", "unknown"),
                "centrality": round(score, 4),
                "connections": self.graph.degree(node),
            })
        return hubs

    def export_graph(self, output_file="infrastructure_graph.json"):
        data = nx.node_link_data(self.graph)
        with open(output_file, "w") as f:
            json.dump(data, f, indent=2)
        print(f"[+] Graph exported: {self.graph.number_of_nodes()} nodes, "
              f"{self.graph.number_of_edges()} edges")

infra_graph = InfrastructureGraph()
discovery = tracker.pivot_from_seed("evil-domain.com", depth=2)
infra_graph.add_discovery(discovery)
clusters = infra_graph.find_clusters()
hubs = infra_graph.find_hub_nodes()
infra_graph.export_graph()
```

### Step 3: Monitor for New Infrastructure

```python
import time

class InfrastructureMonitor:
    def __init__(self, tracker, known_indicators):
        self.tracker = tracker
        self.known = set(known_indicators)
        self.alerts = []

    def check_new_registrations(self, patterns):
        """Check for newly registered domains matching adversary patterns."""
        import re
        new_domains = []
        for pattern in patterns:
            # Query SecurityTrails for new domains matching pattern
            headers = {"apikey": self.tracker.st_key}
            url = "https://api.securitytrails.com/v1/domains/list"
            params = {"include_ips": "true", "page": 1}
            body = {"filter": {"keyword": pattern}}
            resp = requests.post(url, headers=headers, json=body, timeout=30)
            if resp.status_code == 200:
                records = resp.json().get("records", [])
                for record in records:
                    domain = record.get("hostname", "")
                    if domain not in self.known:
                        new_domains.append({
                            "domain": domain,
                            "pattern_matched": pattern,
                            "first_seen": datetime.now().isoformat(),
                        })
                        self.known.add(domain)

        if new_domains:
            print(f"[ALERT] {len(new_domains)} new domains matching patterns")
            self.alerts.extend(new_domains)
        return new_domains

    def generate_infrastructure_report(self, clusters, hubs):
        report = f"""# Adversary Infrastructure Tracking Report
Generated: {datetime.now().isoformat()}

## Summary
- Infrastructure clusters identified: {len(clusters)}
- Total domains tracked: {sum(c['domain_count'] for c in clusters)}
- Total IPs tracked: {sum(c['ip_count'] for c in clusters)}
- New domains detected: {len(self.alerts)}

## Top Infrastructure Hubs
| Node | Type | Connections | Centrality |
|------|------|-------------|------------|
"""
        for hub in hubs[:10]:
            report += (f"| {hub['node']} | {hub['type']} "
                       f"| {hub['connections']} | {hub['centrality']} |\n")

        report += "\n## Infrastructure Clusters\n"
        for i, cluster in enumerate(clusters[:5], 1):
            report += f"\n### Cluster {i} ({cluster['size']} nodes)\n"
            report += f"- Domains: {', '.join(cluster['domains'][:5])}\n"
            report += f"- IPs: {', '.join(cluster['ips'][:5])}\n"

        with open("infrastructure_report.md", "w") as f:
            f.write(report)
        print("[+] Infrastructure report saved")

monitor = InfrastructureMonitor(tracker, known_indicators=set())
```

## Validation Criteria

- Passive DNS queries return historical resolution data
- Reverse IP lookups discover co-hosted domains
- Infrastructure pivoting expands from seed indicators
- Graph analysis identifies clusters and hub nodes
- New infrastructure detected through pattern monitoring
- Reports generated with actionable recommendations

## When NOT to Use

- You need to test what you built (use performing-* skills)
- Task is about configuring existing systems (use configuring-* skills)
- You need to analyze the output (use analyzing-* skills)
- Task is about implementing vendor solutions (use implementing-* skills)
- You don't have infrastructure access
- Task requires compliance validation (use auditing-* skills)


## Red Flags

- Performing actions without explicit written authorization from the asset owner
- Testing against production systems without a defined scope and rules of engagement
- Sharing sensitive findings or credentials in unencrypted communications
- Failing to properly scope and contain the assessment before starting

## Verification

- All steps executed successfully against a test environment before production use
- Output documented with screenshots or logs demonstrating expected behavior
- Results validated against known-good baselines or reference implementations
- Documentation complete enough for another analyst to reproduce findings

## References

- [Juniper: Threat Hunting with Passive DNS](https://blogs.juniper.net/en-us/threat-research/threat-hunting-with-passive-dns-discovering-the-attacker-infrastructure)
- [Censys: Advanced Persistent Infrastructure Tracking](https://censys.com/blog/advanced-persistent-infrastructure-tracking)
- [Embee Research: Malware Infrastructure with DNS Pivoting](https://www.embeeresearch.io/infrastructure-analysis-with-dns-pivoting/)
- [Validin: Passive DNS Threat Hunting](https://www.validin.com/blog/announcing_validin_threat_hunting_platform/)
- [SecurityTrails API](https://securitytrails.com/corp/api)
- [Hunt.io: Uncovering Malicious Infrastructure](https://hunt.io/blog/practical-guide-unconvering-malicious-infrastructure)

## Process

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

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |