In simple English
This tool searches public places on the internet to find email addresses, web addresses, and computer names linked to a company. It helps security professionals check what information is exposed to the public. You can run it from a command line window, through a local web page, or via a web interface. It is free to download and use under an open-source licence, but some of the search providers require paid API keys to return results.
What it is
A reconnaissance application written in Python that collects open-source intelligence from search engines, certificate transparency logs, and threat platforms. It normalizes findings and stores them in a local SQLite database for review.
What it is good for
Security testers and system administrators who need to gather public information about an organization during an authorized security assessment.
- Collects data from dozens of public sources and search providers.
- Includes a local web interface for reviewing run history and tracking changes over time.
- Exports results in JSONL, JSON, and XML formats for automation scripts.
- Requires Python 3.14 and the uv package manager to set up.
- Many discovery sources require their own paid API keys to function properly.
- Misusing active reconnaissance features against unauthorized targets can violate laws and computer use policies.
manual searching across multiple threat intelligence sites and search engines
uv
- projectdiscovery/subfinder15k stars
Focuses primarily on fast subdomain discovery using passive sources.
- owasp-amass/amass15k stars
Performs in-depth network mapping and external asset discovery using graph analysis.
- openbao/openbao8.6k stars
A secrets manager that stores keys and passwords, hands them out on request, and can revoke them.
- future-architect/vuls12k stars
Scans Linux machines over SSH for installed software with publicly reported security holes.
- cossacklabs/acra1.5k stars
A proxy that encrypts individual database fields on the way in and decrypts them on the way out.
git clone https://github.com/laramies/theHarvester.git cd theHarvester uv sync uv run theHarvester -d example.com -b crtsh,certspotter