company_website_info_gathering

Search subdomains
Search in Netlas (app.netlas.io/responses/): host:*.domain.com 
pentest-tools.com/information-gathering/find-subdomains-of-domain
nmmapper.com/sys/tools/subdomainfinder/
Subfinder (github.com/projectdiscovery/subfinder)
Sublist3r (github.com/aboul3la/Sublist3r)
Search possible related websites
Search by organization name in Domain Whois Netlas search (app.netlas.io/whois/domains/)
Search for sites that are served by company-owned mail servers in DNS Netlas search (app.netlas.io/domains/):  mx:*.domain.com 
Search for sites that are served by company-owned name servers in DNS Netlas search (app.netlas.io/domains/): ns:ns?.domain.com
Search by IDs of different services (Google Analytics, affiliate programs) in Netlas (app.netlas.io/responses/): http.body:UA-23870775
Search by uploaded Favicon in Netlas (app.netlas.io/responses/)
Getting a list of website's URLs
Katana (github.com/projectdiscovery/katana)
Waybackurls (github.com/tomnomnom/waybackurls)
Waymore (github.com/xnl-h4ck3r/waymore)
GoBuster (github.com/OJ/gobuster)
Extract "Juicy Info" (social media links, emails, phone numbers, crypto wallets etc) from html pages (without downloading)
Nuclei (github.com/projectdiscovery/nuclei)
"""Juicy Info"" Nuclei templates (github.com/cipher387/juicyinfo-nuclei-templates)"
Download files
Curl (github.com/curl/curl)
Wayback Machine Downloader (github.com/hartator/wayback-machine-downloader)
Search in downloaded files
Grep and alternatives (github.com/cipher387/awesome-grep)
Extract metadata
MetaDetective (github.com/franckferman/MetaDetective)
ExifTool (exiftool.org)
Extract information from PDF documents
Ocrmypdf (github.com/ocrmypdf/OCRmyPDF)
Pdfgrep (pdfgrep.org)
Pdftotext (github.com/jalan/pdftotext)
Pdfimages (xpdfreader.com/pdfimages-man.html)