Adversaries may gather information about the victim's network domain(s) that can be used during targeting. Information about domains and their properties may include a variety of details, including what domain(s) the victim owns as well as administrative data (ex: name, registrar, etc.) and more directly actionable information such as contacts (email addresses and phone numbers), business addresses, and name servers.
Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Information about victim domains and their properties may also be exposed to adversaries via online or other accessible data sets (ex: WHOIS). Where third-party cloud providers are in use, this information may also be exposed through publicly available API endpoints, such as GetUserRealm and autodiscover in Office 365 environments. Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Technical Databases, Search Open Websites/Domains, or Phishing for Information), establishing operational resources (ex: Acquire Infrastructure or Compromise Infrastructure), and/or initial access (ex: Phishing).
This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls. Efforts should focus on minimizing the amount and sensitivity of data available to external parties.
Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.
Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.