Open source intelligence (OSINT) is the act of gathering and analyzing publicly available data for intelligence purposes.

What is open source data?

Open source data is any information that is readily available to the public or can be made available by request. OSINT sources can include:

• Newspaper and magazine articles, as well as media reports
• Academic papers and published research
• Books and other reference materials
• Social media activity
• Census data
• Telephone directories
• Court filings
• Arrest records
• Public trading data
• Public surveys
• Location context data
• Breach or compromise disclosure information
• Publicly shared cyberattack indicators like IP addresses, domain or file hashes
• Certificate or Domain registration data
• Application or system vulnerability data

While most open source data is accessed via the open internet and may be indexed with the help of a search engine like Google, it can also be accessed via more closed forums that are not indexed by search engines. Though most deep web content is inaccessible to general users because it lives behind a paywall or requires a login to access, it is still considered part of the public domain.

It is also important to note that there is often a tremendous amount of secondary data that can be leveraged from each open source of information. For example, social media accounts can be mined for personal information, such as a user’s name, birthdate, family members and place of residence. However, the file metadata from specific posts can also reveal additional information such as where the post was made, the device used to create the file and the author of the file.