Search Closed Sources
Where this stands
No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.
This happens on infrastructure you do not own, so it never reaches your logs. MITRE's own guidance is internet scanning and threat intelligence, not log analysis.
What the technique is
Adversaries may search and gather information about victims from closed (e.g., paid, private, or otherwise not freely available) sources that can be used during targeting. Information about victims may be available for purchase from reputable private sources and databases, such as paid subscriptions to feeds of technical/threat intelligence data. Adversaries may also purchase information from less-reputable sources such as dark web or cybercrime blackmarkets. Adversaries may search in different closed databases depending on what information they seek to gather. Information from these sources may reveal opportunities for other forms of reconnaissance (ex: Phishing for Information or Search Open Websites/Domains), establishing operational resources (ex: Develop Capabilities or Obtain Capabilities), and/or initial access (ex: External Remote Services or Valid Accounts).
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1954
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.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.