What is OSINT? A complete guide to open-source intelligence

Open-source intelligence (OSINT) uses publicly available data to detect data breaches, identify adversaries, and strengthen cybersecurity.

Cybercriminals sell data and plan attacks on the dark web, while phishers become more sophisticated. OSINT counters these trends by collecting publicly available information to identify threat actors.

Open source intel is a valuable tool for journalists, law enforcement, security researchers, and conventional businesses. OSINT can help avoid leaving data breadcrumbs on lesser-known forums, repositories, or outdated web pages. Let's find out how.

What is OSINT

Open Source Intelligence (OSINT) collects and uses publicly available data to answer specific security questions. Cybersecurity analysts use OSINT tools to convert masses of information into usable intelligence. This intelligence helps them understand security risks, detect data leaks, and mitigate critical vulnerabilities.

However, open-source intelligence is not just a defensive asset. Cybercriminals use OSINT techniques to research targets and design phishing attacks.

What qualifies as an “open source” for OSINT purposes?

OSINT uses publicly available information. It does not cover private threat databases or encrypted forums. Instead, OSINT resources include:

• Public records. These include DNS records that help diagnose malicious websites, TLS certificate logs, and historical DNS records where available. OSINT analysts may also consult SEC filings or other business records to assess whether companies are legitimate.
• Media sources. Publicly sold newspapers, magazines, or news websites qualify as open-source intelligence.
• Social media platforms. Includes Twitter profiles and followers, along with professional LinkedIn pages. GitHub can also be useful when verifying developers. Analysts may also have access to public Telegram or Discord servers used by threat actors.
• Vulnerability databases. These databases keep track of current and emerging threats. For example, CVE registers like Exploit-db document known exploits.
• Libraries. Public code libraries help analysts trawl digital records to detect malicious activity. For example, InstaLoader scrapes Instagram profiles for relevant information.
• Image repositories. OSINT sources are not all textual. Analysts may consult image libraries to match the identities of individuals.

Many OSINT definitions also include the Dark Web. The Dark Web is inaccessible to ordinary web users without specialist Tor browsers. However, access is free, and there is no single owner, so the Dark Web qualifies as an OSINT source.

It also hosts marketplaces for stolen credentials and discussion forums to plan attacks, making it one of the most important OSINT tools.

Given the list above, you might wonder what does not qualify as OSINT data. OSINT data must originally be publicly available. This excludes a few classes of data.

For example, leaked or stolen data, proprietary databases like LexisNexis, law enforcement documents, and private messages on social media platforms do not count. Content behind paywalls is generally not deemed open source, nor are internal business records.

How does OSINT work?

OSINT works in several stages. We call these stages the intelligence cycle because the final stage feeds back to the start, creating a positive feedback loop.

Stage 1: Preparation

OSINT starts with an objective. Researchers must define the question they seek to answer. They must then decide how to answer their question accurately. Before venturing into open-source databases, researchers need a road map to an actionable answer, including relevant sources and data points.

Stage 2: Data collection

Next, researchers gather data from reliable public intel sources. Intelligence teams gather as much information as possible, as it helps them answer the overall question. It's important to strike a balance. Excessive data collection swamps analysts, but gathering insufficient data results in low-quality outputs.

OSINT specialists target their searches with scraping tools and code libraries. These tools trawl platforms, websites, and databases, returning answers based on predefined parameters. Analysts can automate most searches, saving time and delivering consistent results.

Note: Analysts generally do not use deception to obtain actionable intelligence (for instance, by creating fake profiles to deceive threat actors).

This method is known as passive intelligence gathering. It contrasts with active techniques that engage directly with suspected threat actors via social networking sites, spoofed emails, or other forms of deception.

Stage 3: Data processing

The next stage turns raw data into usable intelligence. Researchers trim data sets, removing irrelevant information and making data easier to read and interpret.

Meanwhile, data normalization converts many data types into a single format. This makes it possible to search across multiple data sets, making collected data far more powerful.

Stage 4: Analysis and interpretation

Analysts mine intelligence feeds for connections and anomalies. For example, they may detect a pattern of suspicious DNS changes relating to a regular vendor. This could indicate a website hijack or spoofing attack is in progress.

Analysts foreground the original question when writing a report for wider assessment. This report provides a provisional answer for security team leaders to approve or challenge.

Stage 5: Putting threat intelligence to work

After approving the report, security teams disseminate the information to relevant stakeholders. This information helps departments and partners proactively mitigate security risks. For example, analysts may provide a blocklist of unsafe IP addresses or recommend exploit patches.

Dissemination also links back to preparation. OSINT assessments identify critical security vulnerabilities, prompting fresh questions and restarting the intelligence cycle.

Why should businesses use OSINT in their security strategy?

If you have never used open-source intelligence techniques, the OSINT cycle may not seem essential. However, there are several compelling reasons to combine existing network security systems with OSINT tools.

1. OSINT covers every angle

Today's advanced threat intelligence tools search multiple data sources to create in-depth security reports.

Security teams can search website DNS information to find fake websites, alongside social media accounts to find fraudulent contacts. They might also scrape databases of stolen credentials to discover whether individuals are using compromised passwords.

Fighting insurance fraud provides a great example. Fraud investigators now routinely derive OSINT from Facebook profiles and marketplace data. The two services should be distinct, but investigators can use digital evidence to connect sellers and personal profiles.

In this way, insurers can connect reports of stolen goods to marketplace sales of the same items, often solid evidence of fraud.

2. OSINT delivers value for money

Despite using advanced techniques, open-source intelligence can cut cybersecurity costs. OSINT draws insights from publicly available data that can be accessed free of charge. Proactively identifying threat actors also prevents attacks early on, cutting the risk (and cost) of data breaches.

For instance, a small app vendor wants to minimize its exposure to credential theft and supply chain attacks. It uses OSINT to track leaked credentials and detect whether the criminals are discussing the company online.

3. OSINT protects a critical vulnerability: user identities

According to Statista, in 2024, criminals stole over 1.35 billion user credentials in the United States. This includes employee and vendor credentials that threat actors use to breach networks and extract sensitive data.

Unfortunately, victims don't know their credentials are compromised until attacks occur. That's why user identities are currently a critical security concern.

OSINT tools solve this problem. Security teams can monitor dark web marketplaces for employee credentials or mentions of their company. This intelligence allows security teams to alert affected users and force password changes.

4. Companies can adopt a strategic approach to outpace emerging threats

Cybersecurity threats never sleep. In 2024, security experts registered over 6 billion malware attacks worldwide, while over 450,000 new malware agents or unwanted programs appear daily. OSINT provides a way to stay ahead of this surge and meet threats head-on.

For example, a financial institution worries about exploits targeting its client database. Security professionals use OSINT tools to scrape dark web forums, looking for mentions of software the company uses.

Simultaneously, OSINT experts look for mentions of the financial brand to detect suspicious discussions and assess attacks against similar companies to discover current threat vectors.

OSINT: Critical challenges for security teams

OSINT is powerful, but it is not a magic bullet. Companies regularly encounter problems when exploiting public records and other intelligence sources. Common bottlenecks include:

Being overwhelmed by too much data

How much data is enough to answer your critical cybersecurity question? OSINT teams can easily become overloaded with data, generating noise and making it harder to discern actionable intelligence.

Teams with too much data to handle become bogged down. Analysts take longer to parse data and identify threats, while costs rise accordingly.

Poorly designed metrics generate false positives. Data feeds may flag benign activity as a potential threat or - even worse - overlook genuine threats. Meanwhile, security teams struggling with false positives are prone to fatigue and poor performance.

Choosing reliable information sources

Not all OSINT sources are equal. A single inaccurate source can amplify false positives and contaminate security reports. Threat actors can mislead investigators with inaccurate information, while sources become outdated, making their information far less useful.

Security teams need processes to verify information and sources. Regularly assess the sources you use and jettison databases or methods that underperform.

Updating techniques to reflect current threats

In a world of ever-changing threats, keeping your OSINT framework current is critical. Without updated intelligence, companies may search for yesterday's threat actors and allow active collectives to launch attacks.

Regulations evolve, potentially making OSINT techniques illegal (or enabling previously inaccessible methods). Tools evolve, making it vital to assess vendor performance and choose the best providers.

Updating skills is just as essential. Teams need regular training to use cutting-edge OSINT techniques effectively. For example, artificial intelligence and machine learning empower OSINT teams, potentially accelerating the intelligence cycle. However, only companies with the right skill set will realize the benefits.

Setting ethical boundaries

OSINT techniques often collide with privacy and data protection concerns. Security teams must identify threat actors without compromising user privacy. Codes of conduct are vital to prevent threat identification without robust evidence.

Similarly, teams need clear boundaries about acceptable and unacceptable information sources. Scraping semi-private databases may breach local data protection laws (especially in the European Union, where GDPR applies).

Reckless use of OSINT data collection can damage corporate reputations. So use data analysis tools wisely, and stay focused on specific security vulnerabilities.

Types of open-source intelligence tools

Open-source intelligence strategies rely on specialist tools to extract, organize, and analyze data. With that in mind, the following tools could be wise additions to your OSINT framework.

Tools to analyze social media platforms

Social media analytics tools scrape social media platforms for open-source intelligence. Companies can search LinkedIn, Twitter, Facebook, Instagram, and specialist forums to detect mentions of their brand. Analytics tools can monitor engagement spikes (such as unusual hashtags) that could indicate an incoming attack.

Artificial intelligence supplements basic social media analysis. AI enables sentiment analysis to separate normal discussions from malicious content or brand impersonation.

Web data analysis tools

These tools analyze domain registrations, DNS information, and IP addresses. By comparing website data with the signatures of legitimate sites, OSINT technicians can identify malicious websites and block phishing attacks via web filtering blocklists.

Deep and dark web monitoring

The dark web is a playground for threat actors, offering a place to source login details, forge connections, and launch attacks. OSINT tools monitor the dark web for mentions of a company, critical vendors, or leaked credentials.

Advanced dark web monitoring tools like NordStellar allow security teams to alert users when data leaks compromise their credentials. Dark web intelligence may uncover illicit data sales by insiders or provide pointers about upcoming attacks.

File metadata analysis

Security teams use OSINT to assess incoming documents or file downloads and determine whether they are safe. Investigators use file headers and logs to identify the file's creator and look for embedded code or malicious macros.

OSINT techniques

So far, we've discussed tools and benefits for open source intelligence. However, it's important to dig deeper and examine some core OSINT techniques. OSINT is surprisingly powerful and granular, and it goes far beyond basic keyword searches.

Common features of OSINT tools include:

EXIF extraction and file metadata

Exchangeable Image File Format (EXIF) extraction examines suspicious files. Analysts examine timestamps and geolocation data to identify when and where files were edited. Tools identify the software used to make edits and even device information.

Data cross-referencing

Cross-referencing turbo-charges OSINT by leveraging multiple data sets. Investigators can verify data by comparing different sources. Using many data points (including IP addresses, DNS, or forum posts) adds depth to threat analysis and attribution. Security teams get a full picture of attack patterns and likely techniques.

IP address and domain analysis

OSINT teams analyze IP addresses and website domain names to verify the legitimacy of sites and individuals. They may look at historical DNS changes to detect impersonation, or consult global databases of IP addresses connected to previous attacks.

Threat monitoring

Security teams actively monitor discussions on Dark Web forums, mainstream social media sites, and communication platforms like Discord and Telegram. Sometimes, this may require active reconnaissance (for example, by scanning server ports or assuming fake identities to access restricted sites).

Advanced searches allow OSINT specialists to home in on relevant discussions to detect mentions of future attacks or leaked hashes and credentials.

What are the main use cases of OSINT?

Cybersecurity technologies are only effective when used properly. Open-source intelligence is no exception. Fortunately, OSINT tools have many use cases for small, medium, and large enterprises. We've chosen a few use cases from many, and one will most likely apply to your operations.

Protecting your brand reputation online

Cybercriminals can spoof brands to sell counterfeit products, write phishing emails, or divert customers to malicious websites. Companies must know when spoofing occurs and act quickly to dismantle criminal activity.

OSINT helps track dark web forums and social media accounts for brand mentions. Scanning tools detect fake websites linked to a company's brand and help identify the culprits.

OSINT tools also help detect exposed credentials and potential data leaks. This intelligence helps companies maintain customer trust by minimizing data theft and alerting customers when incidents occur.

Maintaining robust cybersecurity

In today's digital economy, effective cybersecurity is proactive and based on threat intelligence. Using open-source intelligence allows companies to monitor current threats, detect attacks early on, and stay ahead of their adversaries.

Security teams can use OSINT data collection to learn about threat vectors. That way, companies can improve their security posture before attacks occur. Naturally, network security tools are critically important. OSINT supplements them, enabling targeted security measures.

Preventing corporate espionage and insider threats

Companies face an ever-present threat of intellectual property theft or corporate sabotage. OSINT techniques detect the warning signs of corporate espionage.

Social media searches detect posts from alienated employees (or worse, posts on the dark web). Web, image, and social media searches help companies screen employees and filter security risks. OSINT searches detect leaked credentials or confidential documents before adversaries can monetize them.

Journalism and fact-checking

The media industry uses OSINT to verify sources and investigate stories. For instance, news organizations must constantly check the accuracy of photographs and videos, which is becoming increasingly challenging as AI develops. Often, OSINT is the only solution, allowing companies to check the identity of sources, the location of images, and the metadata underlying them.

Strengthening compliance strategies

OSINT also helps companies meet their data security and privacy compliance goals. Scanning tools allow compliance teams to identify leaked data and take appropriate action. OSINT helps companies assess vendors and cut supply chain risks. Intelligence also makes it easier to investigate insider threats and protect internal systems.

How is OSINT used in cybersecurity?

OSINT has many use cases, but strengthening cybersecurity is the most important. Cybersecurity experts use OSINT to:

• Detect ongoing and past data breaches
• Diagnose the causes of data breaches and implement security controls
• Analyze threat actors and counter relevant attack methods
• Identify phishing attacks and inform stakeholders
• Analyze downloads and documents to identify threats
• Discover malicious websites and who is behind them

Put OSINT to work: strengthen your security with NordStellar

Proactive security strategies detect and mitigate threats before they reach the public eye. NordStellar equips your team with deep visibility into external threats, exploring parts of the internet where conventional security tools won't go.

NordStellar uses OSINT to deliver comprehensive cyber threat visibility. Users can easily scan dark web sources for company mentions and leaked emails or credentials. Anti-cybersquatting tools help defeat spoofers. Attack Surface Management (ASM) also scans your network edge, detecting security vulnerabilities.

With NordStellar, you can act on real-time intelligence, protect sensitive data, and reduce your risk, without adding complexity to your stack.