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| OSINT |
Learn how to detect phishing campaigns using OSINT (Open Source Intelligence). Explore top techniques and tools for identifying fake domains, malicious emails, and social engineering attempts to strengthen your cybersecurity.
Phishing attacks target individuals and organizations by impersonating legitimate entities to trick victims into revealing sensitive information. These attacks often lead to data breaches, identity theft, and ransomware infections.
Traditional email filters and antivirus programs may miss new or evolving threats. This is where OSINT shines by collecting and analyzing publicly available data in real time, investigators can uncover phishing campaigns before they cause damage.
“The best way to fight phishing is to recognize its signals before it reaches inbox.”
What is OSINT in Phishing Detection?
OSINT (Open Source Intelligence) refers to gathering intelligence from publicly available sources. In phishing detection, OSINT helps cybersecurity teams:
- Identify spoofed websites and domains
- Monitor suspicious URL registrations
- Track phishing kits and attacker infrastructure
- Analyze threat actor behavior across forums and platforms
Unlike internal threat detection, OSINT focuses on external environment, making it especially useful for identifying emerging threats.
Common Phishing Indicators Detected via OSINT
| Indicator | Description |
|---|---|
| Lookalike Domains | Slight variations of trusted domains (e.g., paypa1.com) |
| Recent Domain Registrations | New domains used in phishing often have minimal history |
| Malicious IP Addresses | IPs with spam, malware, or phishing history |
| SSL Certificates Misuse | Free or short term SSL certs used for phishing |
| Fake Login Pages | Hosted on spoofed domains with login forms |
| Dark Web Chatter | Threat actors selling phishing kits or targeting specific companies |
Top OSINT Techniques for Phishing Detection
1. Domain and Subdomain Monitoring
Track newly registered domains or subdomains that resemble legitimate services.
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Technique: Use domain registrars and WHOIS lookups to find suspicious patterns.
2. Certificate Transparency Logs
Check SSL certificates issued for typo squatted domains.
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Technique: Monitor CT logs using tools like crt.sh or Censys to identify domains imitating your brand.
3. Email Header and Metadata Analysis
Extract and analyze metadata from suspicious emails.
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Technique: Use tools to trace IP origins, mail servers, and anomalies in DKIM/SPF.
4. Phishing Kit Tracking
Some phishing kits reuse same code or file structures.
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Technique: Search GitHub, forums, or public repositories for phishing kits and indicators of compromise (IOCs).
5. Social Media and Paste Site Monitoring
Threat actors often leak stolen credentials or phishing links on sites like Pastebin, Telegram, or dark web forums.
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Technique: Use crawlers and alert systems to detect mentions of your company or URLs.
Recommended OSINT Tools for Phishing Detection
| Tool | Function |
|---|---|
| VirusTotal | Scan suspicious URLs and files for malware/phishing indicators |
| PhishTool | Analyze and classify phishing emails with machine learning |
| urlscan.io | Visualize and inspect suspicious URLs in sandboxed environments |
| theHarvester | Gather emails, domains, subdomains, and more |
| Shodan & Censys | Detect exposed infrastructure or command and control servers |
| ThreatFox | IOC repository for phishing and malware indicators |
A cybersecurity team identified a phishing domain mimicking their company’s login portal by monitoring crt.sh and urlscan.io. Using OSINT, they:
- Discovered domain registered 48 hours earlier
- Found it hosted a login form cloned from their official website
- Worked with domain registrars to issue a takedown request
- Informed users before phishing campaign went live
Ready to improve your phishing defense strategy with OSINT?
