Query: EDR alert: possible Device Registration (T1098.005)
Matching passage: T1098.005 Device Registration. Tactics: persistence, privilege escalation. Description: Adversaries may register a device to an adversary-controlled account. Devices may be registered in a multifactor authentication (MFA) system, which handles authentication to the network, or in a device management system, which handles device access and compliance. MFA systems, such as Duo or Okta, allow users to associate devices with their accounts in order to complete MFA requirements. An adversary that compromises a user’s credentials may enroll a new device in order to bypass initial MFA requirements and gain persistent access to a network.(Citation: CISA MFA PrintNightmare)(Citation: DarkReading FireEye SolarWinds) In some cases, the MFA self-enrollment process may require only a username and password to enroll the account's first device or to enroll a device to an inactive account. (Citation: Mandiant APT29 Microsoft 365 2022) Similarly, an adversary with existing access to a network may register a device or a virtual machine to Entra ID and/or its device management system, Microsoft Intune, in order to access sensitive data or resources while bypassing conditional access policies.(Citation: AADInternals - Device Registration)(Citation: AADInternals - Conditional Access Bypass)(Citation: Microsoft DEV-0537)(Citation: Expel Atlas Lion 2025) Devices registered in Entra ID may be able to conduct [Internal Spearphishing](https://attack.mitre.org/techniques/T1534) campaigns via intra-organizational emails, which are less likely to be treated as suspicious by the email client.(Citation: Microsoft - Device Registration) Additionally, an adversary may be able to perform a [Service Exhaustion Flood](https://attack.mitre.org/techniques/T1499/002) on an Entra ID tenant by registering a large number of devices.(Citation: AADInternals - BPRT)
Near-miss passage: T1098.007 Additional Local or Domain Groups. Tactics: persistence, privilege escalation. Description: An adversary may add additional local or domain groups to an adversary-controlled account to maintain persistent access to a system or domain. On Windows, accounts may use the `net localgroup` and `net group` commands to add existing users to local and domain groups.(Citation: Microsoft Net Localgroup)(Citation: Microsoft Net Group) On Linux, adversaries may use the `usermod` command for the same purpose.(Citation: Linux Usermod) For example, accounts may be added to the local administrators group on Windows devices to maintain elevated privileges. They may also be added to the Remote Desktop Users group, which allows them to leverage [Remote Desktop Protocol](https://attack.mitre.org/techniques/T1021/001) to log into the endpoints in the future.(Citation: Microsoft RDP Logons) Adversaries may also add accounts to VPN user groups to gain future persistence on the network.(Citation: Cyber Security News) On Linux, accounts may be added to the sudoers group, allowing them to persistently leverage [Sudo and Sudo Caching](https://attack.mitre.org/techniques/T1548/003) for elevated privileges. In Windows environments, machine accounts may also be added to domain groups. This allows the local SYSTEM account to gain privileges on the domain.(Citation: RootDSE AD Detection 2022)