Reconnaissance & OSINT

When to Activate

• A new engagement begins and you need a full external attack-surface map for a set of root domains / ASNs.
• Expanding scope: pivoting from one discovered asset (subdomain, IP block, cloud account) to the rest of the estate.
• Hunting dangling DNS / subdomain-takeover candidates, including S3 buckets referenced by CI/CD assets.
• Building a target profile for social engineering / initial access (emails, usernames, breach + infostealer exposure).
• Discovering leaked secrets in public GitHub/GitLab orgs and exposed cloud storage.
• Triaging which discovered CVEs actually matter (KEV + EPSS + exposure) before weaponization.

Technique Map

Technique	ATT&CK	CWE	Reference	Script
Passive subdomain enum (subfinder/amass/CT logs)	T1590.002, T1596.001	CWE-200	references/subdomain-discovery.md	scripts/recon_orchestrator.py
DNS brute / permutation / resolution (puredns/alterx/dnsx)	T1595.002, T1590.002	CWE-200	references/subdomain-discovery.md	scripts/recon_orchestrator.py
ASN → CIDR → reverse-DNS expansion	T1590.005, T1596.005	CWE-200	references/subdomain-discovery.md	scripts/recon_orchestrator.py
HTTP probing + tech fingerprint (httpx)	T1595.002, T1592.002	CWE-200	references/attack-surface-mapping.md	scripts/recon_orchestrator.py
Headless crawling + archive URLs (katana/gau)	T1595.002, T1593.003	CWE-200	references/attack-surface-mapping.md	scripts/js_secret_hunter.py
JavaScript endpoint / secret extraction	T1593.003, T1552.001	CWE-540	references/attack-surface-mapping.md	scripts/js_secret_hunter.py
Subdomain takeover (dangling CNAME/NS)	T1583.001, T1584.001	CWE-350	references/subdomain-takeover.md	scripts/subdomain_takeover.py
Deleted-S3 takeover → supply-chain pivot	T1583.001, T1195.002	CWE-350	references/subdomain-takeover.md	scripts/subdomain_takeover.py
Multi-cloud bucket/blob enum (cloud_enum)	T1580, T1596.005	CWE-732	references/cloud-saas-recon.md	scripts/cloud_asset_enum.py
Azure tenant outsider recon (AADInternals)	T1590.001, T1589	CWE-200	references/cloud-saas-recon.md	scripts/cloud_asset_enum.py
GitHub/GitLab dorking + secret scanning	T1593.003, T1213.003	CWE-540	references/cloud-saas-recon.md	scripts/cloud_asset_enum.py
Email/username harvesting (theHarvester)	T1589.002, T1591	CWE-200	references/breach-credential-intel.md	scripts/breach_intel.py
Breach + infostealer credential intel (HIBP/DeHashed)	T1589.001, T1596	CWE-522	references/breach-credential-intel.md	scripts/breach_intel.py
CVE enrichment + prioritization (NVD/EPSS/KEV)	T1592.002, T1596	CWE-1395	references/cve-exploit-intel.md	scripts/cve_prioritizer.py
Shodan InternetDB exposure → CVE mapping	T1596.005, T1595.002	CWE-200	references/cve-exploit-intel.md	scripts/cve_prioritizer.py

Quick Start

export DOMAIN=target.com
# 0. Validate resolvers once (puredns needs a clean list)
dnsvalidator -tL https://public-dns.info/nameservers.txt -threads 100 -o resolvers.txt

# 1. Full discovery + probe + crawl + takeover + nuclei, JSONL out (see orchestrator)
python3 scripts/recon_orchestrator.py -d $DOMAIN -o out/ --resolvers resolvers.txt --nuclei

# 2. JS/endpoint + secret hunting over live hosts
python3 scripts/js_secret_hunter.py -l out/httpx_live.txt -o out/js/

# 3. Dangling-DNS / subdomain-takeover triage
python3 scripts/subdomain_takeover.py -l out/all_subdomains.txt -o out/takeovers.jsonl

# 4. Cloud + code recon (buckets, Azure tenant, GitHub secrets)
python3 scripts/cloud_asset_enum.py -k $DOMAIN --company target --azure-domain $DOMAIN --gh-org target

# 5. People + breach/infostealer intel
python3 scripts/breach_intel.py --domain $DOMAIN --harvest --hibp --dehashed

# 6. Triage CVEs from fingerprints → KEV/EPSS/exposure ranked
python3 scripts/cve_prioritizer.py --from-httpx out/httpx_live.txt --ip-file out/ips.txt -o out/cve_ranked.jsonl

OPSEC & Detection (summary)

Technique	Telemetry / IOC	Detection (Sigma/EDR)	OPSEC note
Passive enum (CT/API)	None on target; queries hit 3rd-party APIs	Target cannot see it; CT-log monitoring (certstream) detects new certs only	Fully passive — prefer for stealth; no target traffic
DNS brute / resolution	Burst of NXDOMAIN/A queries to authoritative + resolvers	DNS firewall: high-volume distinct-label rate per source IP; Zeek dns.cc/NXDOMAIN ratio	Throttle -rate, rotate resolvers, never brute a single auth NS directly
httpx / katana probing	Spike of HTTP(S) requests, odd UA, favicon/JARM fetches	WAF/CDN: request-rate + UA anomaly; access-log User-Agent: *httpx*/*katana*	Set custom UA, low -rl, route via proxy pool / cloud egress
Subdomain takeover check	HTTP GET to dangling host (lands on 3rd-party)	3rd-party provider logs; CT for new cert on claimed host	Verify with passive fingerprint before any claim; claiming is loud
Cloud bucket enum	DNS + HTTP to *.s3/blob/storage.googleapis	Cloud provider access logs; GuardDuty Discovery:S3/*	Hits provider, not target; still rate-limited / loggable
Azure tenant recon	Requests to login.microsoftonline.com	Entra sign-in/audit logs do not see unauth realm probes	getuserrealm/OpenID are unauth & invisible to tenant
GitHub/GitLab dorking	API/search queries from your token	GitHub audit log (only org members'); secret-scanning alerts	Use a throwaway token; respect rate limits to avoid bans
Breach/infostealer lookup	3rd-party API calls (HIBP/DeHashed)	None on target	Handle PII per ROE/GDPR; document lawful basis
CVE enrichment	NVD/EPSS/KEV/Shodan API calls	None on target	Map exposure to in-scope assets only

Deep Dives

• references/subdomain-discovery.md — Passive sources + CT logs, puredns/massdns resolution, alterx permutations, ASN→CIDR→PTR expansion, wildcard handling.
• references/attack-surface-mapping.md — httpx enrichment (-td -favicon -jarm -asn), katana headless/authenticated crawling, gau/wayback archive mining, JS endpoint + secret extraction, nuclei triage of the live set.
• references/subdomain-takeover.md — Dangling-DNS theory, can-i-take-over-xyz fingerprints, subzy/baddns/nuclei detection, the 2024-2025 deleted-S3 → CI/CD supply-chain pivot, NS-delegation takeover.
• references/cloud-saas-recon.md — cloud_enum multi-cloud, AADInternals/MicroBurst Azure tenant + blob recon (incl. the June-2025 Get-AADIntTenantDomains patch), GrayhatWarfare, GitHub/GitLab dorking with trufflehog/gitleaks/noseyparker.
• references/breach-credential-intel.md — theHarvester 4.x, HIBP API v3 (ALIEN TXTBASE), DeHashed, infostealer-log intel (Snowflake-style aged creds), username/email format derivation, password-pattern modeling.
• references/cve-exploit-intel.md — NVD 2.0 API + the 2026 selective-enrichment shift, EPSS v4, CISA KEV, Shodan InternetDB, searchsploit/nuclei, the KEV×EPSS×exposure prioritization stack.