Introduction
In the age of (almost) everything digital, where every click, publication or online interaction generates traces, the collection of publicly accessible information, also known as OSINT (Open Source Intelligence), has become an essential discipline.
Originating in traditional intelligence, OSINT has adapted to the digital world to become a cornerstone of cybersecurity. Whether it’s monitoring threats, identifying vulnerabilities or investigating incidents, cybersecurity OSINT makes it possible to take advantage of freely accessible data to protect individuals and organisations.
In this article, we present its key principles, techniques and tools. We also detail the methodology and process of a cybersecurity OSINT, using a concrete case study.
Comprehensive Guide to Cybersecurity OSINT
What is OSINT (Open Source Intelligence)?
OSINT (Open Source Intelligence) focuses on researching and exploiting publicly available information. This information can come from a variety of channels: websites, social networks, forums, public databases, newspapers, legal documents, etc.
Unlike espionage or hacking methods, OSINT is based on legal and often passive information gathering, which distinguishes it from other intrusive practices.
Cybersecurity OSINT
In cybersecurity, OSINT plays a key role in identifying vulnerabilities, understanding potential threats, and making decisions to protect digital assets.
For example, an auditor can use OSINT to detect credentials exposed on the dark web, identify forgotten subdomains of a company, or map a target’s technical infrastructure from publicly available information.
One of the strengths of OSINT lies in its ability to transform a mass of raw data into actionable intelligence. However, this requires a rigorous methodology (to which we will return later in this article):
- Clearly define the objectives. What are we trying to find out? For example, an audit might aim to assess the online exposure of a specific system.
- Identify the relevant sources. These sources can vary depending on the objectives, ranging from advanced search engines (Google Dorking) to specialist platforms such as Shodan or Censys.
- Check the reliability of the data. Not all the information available online is accurate or relevant. Cross-checking data and analysing its origin is essential.
What are the applications of OSINT?
OSINT is not limited to technical audits; it is also used for:
- Digital investigations: As part of a fraud or phishing campaign, OSINT can help to trace the origin of an attack by analysing the infrastructures used or the associated digital profiles.
- Strategic intelligence: Companies use OSINT to monitor their competitors, detect leaks of sensitive information or anticipate market developments.
- Crisis management: In the event of a cybersecurity incident, OSINT can be used to quickly assess the extent of the damage, for example by checking whether sensitive data has been published.
OSINT Challenges and limitations
Despite its many advantages, OSINT is not without its challenges. The first limitation is legality.
Although the information collected is public, certain practices can cross the line of legality, particularly when it comes to personal data. In Europe, the GDPR imposes strict restrictions on the collection and use of such data.
In addition, information overload can be an obstacle. With the explosion of data accessible online, it’s easy to get lost or waste time on irrelevant data.
A good mastery of the tools and an effective methodology are therefore essential if you are to take full advantage of OSINT.
Why cybersecurity OSINT is essential today
As organisations go digital, their attack surfaces increase. From poorly secured configurations (such as public S3 buckets on AWS) to compromised credentials, exposed information can become a gateway for attackers.
By identifying these vulnerabilities in advance, cybersecurity OSINT acts as an essential safety net in the prevention of cyber attacks.
In this way, OSINT is not just a technical skill; it is a strategic practice which, if used properly, can make the difference between falling victim to an attack or avoiding it in time.
OSINT Techniques and Tools
OSINT is based on a range of techniques for collecting, exploiting and interpreting publicly available information. These techniques are adapted to the nature of the data sought and the context of an investigation.
Although they are varied, they share a common objective: to reveal crucial information without breaking the law.
Here are the main methods for conducting a cybersecurity OSINT.
Google Hacking (Google Dorking)
Google Dorking or Google Hacking is an advanced technique that uses specific operators to query search engines in a targeted way.
These operators can be used to search for files or pages that are often ignored in traditional queries.
For example, using the filetype: operator can help locate sensitive documents exposed online, such as PDF files containing confidential information. A query such as site:example.com filetype:pdf ‘confidential’ can reveal documents belonging to a company. Other operators such as inurl: or intitle: can be used to identify poorly protected management interfaces or forgotten pages.
Although powerful, Google Dorking requires a detailed knowledge of operators and their combinations to avoid unnecessary results.
This technique is particularly useful for mapping an organisation’s digital resources or identifying configuration errors, such as unsecured directories or exposed logs.
Mapping technical infrastructures
Cybersecurity OSINT is not limited to personal or textual information. It also extends to technical data, including IP addresses, domain names and server configurations.
Tools such as Shodan or Censys can scan the web for connected devices and exposed services. These tools can reveal critical vulnerabilities, such as misconfigured servers that are publicly accessible or databases that are left open without authentication.
For example, a simple search on Shodan with a filter such as port:22 country: ‘FR’ can list SSH servers open in France, providing an overview of infrastructures likely to be targeted.
In addition, tools such as DomainTools or Sublist3r can be used to identify sub-domains associated with an organisation, which are often forgotten but still active. These sub-domains can reveal unattended development or test environments.
Exploring public databases
Public databases are an invaluable source of legitimate and legal information. Registries such as Whois provide details of domain name owners and registration details, while platforms such as Pastebin or GitHub can contain sensitive information that is accidentally leaked.
In cybersecurity, searching sites specialising in data breaches, such as Have I Been Pwned, can help identify compromised credentials or exposed passwords. This method is particularly useful for assessing the impact of a data leak or for making users aware of their personal risks.
Metadata analysis
Every file, photo or video contains embedded metadata, which is often overlooked but rich in information. This metadata can include geolocation, the software used to create the file, the creation date, or even the user’s name.
Tools such as ExifTool or Metagoofil can extract this data in an instant. For example, a photo published online can reveal the GPS coordinates of the place where it was taken, providing valuable clues as to a person’s movements or activities.
In a professional context, analysing documents downloaded from a site can reveal internal information, such as the path of network directories or the names of file authors, offering clues about the internal organisation of a company.
Data collection on social networks
Social networks are an inexhaustible source of data, ranging from personal information to lifestyle habits and interpersonal or professional relationships.
Platforms such as LinkedIn and Twitter are full of content that is often published without any awareness of the risks involved.
Techniques for exploring social networks include:
- Profile analysis: Identify professional information on LinkedIn, such as the technologies used by a company or employee contact details.
- Advanced search: Exploit native social network tools, such as Twitter search filters to track specific hashtags or monitor public mentions.
- Relationship mapping: Use tools like Maltego to visualise connections between individuals and organisations.
This exploration can also be extended to less visible platforms, such as forums, which often require discreet access techniques to avoid arousing suspicion.
Cybersecurity OSINT Methodology
To illustrate the methodology and impact of a cybersecurity OSINT, let’s take the example of an audit we carried out for a company in the technology sector, which we’ll refer to here as TechSphere.
The company, which operates internationally, wanted to assess its online exposure in order to better protect its digital assets in the face of growing cyber threats.
Defining objectives and scoping the mission
Before getting started, we worked closely with the TechSphere team to define the project objectives. These included:
- Identifying exposed digital assets (websites, subdomains, IP addresses, etc.).
- Identifying publicly accessible sensitive information, including technical and human data.
- Assessing the risks associated with the external attack surface.
- Propose concrete recommendations for reducing vulnerabilities.
This process enabled us to set the limits of the scope, while complying with OSINT’s legal and ethical requirements.
Collecting technical data
The collection phase began with an in-depth analysis of TechSphere’s digital assets.
Using a combination of specialist tools and proven techniques, we gathered key information, such as :
- Mapping of exposed sub-domains and services: Using tools such as Sublist3r, we identified several active but forgotten sub-domains, including publicly accessible development and test environments. Analysis via Shodan and Censys revealed that some of these services were using outdated versions of software, exposing TechSphere to CVEs.
- Analysis of server configurations: An in-depth search of public configurations revealed errors in the implementation of security protocols. For example, unused ports were open, and some SSL certificates were expired or misconfigured, increasing the risk of exploitation.
- Data in public repositories: While exploring platforms such as GitHub, we discovered unprotected repositories containing source code and API keys, exposing critical elements of TechSphere’s infrastructure. These repositories, created by internal developers, had not been properly secured or listed by the company.
Collecting human data
In addition to the technical analysis, we conducted research on TechSphere employees to assess the company’s human exposure:
- Profiling on LinkedIn and Twitter: We identified employees who had publicly shared sensitive information, such as the tools and technologies used by the company, or even screenshots of projects in progress. This information could be exploited by attackers to create targeted phishing scenarios.
- Leakage of credentials: Using databases such as Have I Been Pwned and searching dark web forums, we detected employee credentials compromised in past data breaches. Some of these identifiers used passwords that were reused on several accounts, increasing the risk of credential stuffing attacks.
- Mapping interpersonal relationships: With Maltego, we established connections between employee profiles and subcontractors, revealing potential links that could be exploited for indirect attacks.
Identifying potential vulnerabilities
Based on the data collected, we identified several critical vulnerabilities:
- Accessible test environments: These environments, often overlooked, contained real data and allowed potential access to production.
- Exposed code repositories: The presence of API keys and unsecured configuration files provided an entry point for attackers.
- Compromised credentials: The reuse of passwords compromised the integrity of internal systems.
- Human exposure: Information shared on social networks facilitated social engineering attacks, such as spear phishing campaigns targeting key employees.
Simulated attack scenarios
Based on the vulnerabilities identified, we have developed several attack scenarios that attackers could have exploited:
- Access using a forgotten sub-domain: by exploiting an exposed test environment, an attacker could have retrieved sensitive database information and gained unauthorised access to the system.
- Credential stuffing attack: using compromised credentials, it was possible to attempt to gain access to the company’s internal platforms, such as email services or project management tools.
- Targeted social engineering: using information gathered from social networks, an attacker could have designed highly personalised emails to encourage employees to download a malicious file or share confidential information.
These scenarios were simulated in a controlled environment to demonstrate their feasibility and make TechSphere teams aware of their real exposure.
Recommendations following the cybersecurity OSINT
For each vulnerability identified, we have provided specific recommendations. These include:
- Reduce the technical attack surface:
- Set up a centralised inventory of active sub-domains and services.
- Restrict access to test environments and isolate them from production systems.
- Reinforce human security:
- Make employees aware of the use of social networks and how to manage their digital footprint.
- Implement a password management policy, including the use of a secure password manager and the systematic activation of multi-factor authentication (MFA).
- Protect code repositories:
- Adopt best GitHub management practices, such as securing private repositories and using secrets manager to protect access keys.
- Implement a security review process before any deployment.
- Reinforce continuous OSINT monitoring:
- Integrate a threat intelligence programme to quickly detect new leaks or exposures.
- Carry out regular OSINT audits to maintain a high level of security.
Results and impacts
Thanks to this assessment, TechSphere was able to identify critical vulnerabilities before they were exploited, and implement appropriate corrective measures.
The OSINT report, including mapping, technical analysis and strategic recommendations, also helped to raise awareness of the risks associated with digital exposure among all teams, from developers to senior management.
This example illustrates how Vaadata’s OSINT approach, combining technical expertise with an understanding of human issues, helps organisations to effectively reduce their attack surface and strengthen their security posture in the face of an ever-changing digital environment.
Conclusion
OSINT has become a key discipline in the field of cybersecurity.
By exploiting public information available online, this method helps to prevent threats, detect potential vulnerabilities and respond effectively to cyber attacks.
However, mastering OSINT requires not only an in-depth knowledge of techniques and tools, but also a rigorous approach to ensuring compliance with current regulations.
For organisations, cybersecurity OSINT is a powerful lever for proactive protection. Mapping their attack surface, identifying exposed data and assessing their exposure to cyber threats are becoming critical steps to avoid being caught off guard.
At a time when cyber attacks are becoming increasingly frequent and sophisticated, calling in OSINT experts is an essential strategic move.
Vaadata, a company specialising in offensive security, can help you map exposed digital assets, identify exploitable vulnerabilities and put forward practical recommendations for strengthening your security.
Author: Amin TRAORÉ – CMO @Vaadata