Gather Victim Network Information: Network Security Appliances
Before compromising a victim, adversaries may gather information about the victim's network security appliances that can be used during targeting. Information about network security appliances may include a variety of details, such as the existence and specifics of deployed firewalls, content filters, and proxies/bastion hosts. Adversaries may also target information about victim network-based intrusion detection systems (NIDS) or other appliances related to defensive cybersecurity operations.
Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Information about network security appliances may also be exposed to adversaries via online or other accessible data sets (ex: Search Victim-Owned Websites). Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Technical Databases or Search Open Websites/Domains), establishing operational resources (ex: Develop Capabilities or Obtain Capabilities), and/or initial access (ex: External Remote Services).
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.