Adversaries may hijack domains and/or subdomains that can be used during targeting. Domain registration hijacking is the act of changing the registration of a domain name without the permission of the original registrant.(Citation: ICANNDomainNameHijacking) Adversaries may gain access to an email account for the person listed as the owner of the domain. The adversary can then claim that they forgot their password in order to make changes to the domain registration. Other possibilities include social engineering a domain registration help desk to gain access to an account, taking advantage of renewal process gaps, or compromising a cloud service that enables managing domains (e.g., AWS Route53).(Citation: Krebs DNS Hijack 2019) Subdomain hijacking can occur when organizations have DNS entries that point to non-existent or deprovisioned resources. In such cases, an adversary may take control of a subdomain to conduct operations with the benefit of the trust associated with that domain.(Citation: Microsoft Sub Takeover 2020) Adversaries who compromise a domain may also engage in domain shadowing by creating malicious subdomains under their control while keeping any existing DNS records. As service will not be disrupted, the malicious subdomains may go unnoticed for long periods of time.(Citation: Palo Alto Unit 42 Domain Shadowing 2022)
Monitor for logged domain name system (DNS) registry data that may hijack domains and/or subdomains that can be used during targeting. In some cases, abnormal subdomain IP addresses (such as those originating in a different country from the root domain) may indicate a malicious subdomain.(Citation: Palo Alto Unit 42 Domain Shadowing 2022) Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Command and Control. Consider monitoring for anomalous changes to domain registrant information and/or domain resolution information that may indicate the compromise of a domain. Efforts may need to be tailored to specific domains of interest as benign registration and resolution changes are a common occurrence on the internet. Monitor for queried domain name system (DNS) registry data that may hijack domains and/or subdomains that can be used during targeting. In some cases, abnormal subdomain IP addresses (such as those originating in a different country from the root domain) may indicate a malicious subdomain.(Citation: Palo Alto Unit 42 Domain Shadowing 2022) Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Command and Control.