T1078No distinct observable

Valid Accounts

Stealth · Persistence · Privilege Escalation · Initial AccessContainers, ESXi, IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, SaaS, Windows

Where this stands

A reviewer read the telemetry and concluded there is nothing here to detect that a sibling technique does not already cover.

Every analytic in DET0560 is a baseline-comparison problem, and the residue that is not is already a child's mechanism. AN1543 (Windows) asks to flag logon types 'unexpected... for sensitive accounts', an acceptable-hours 'TimeWindow', and a 'GeoIPMismatch' against prior user behavior — all three need a per-account history lib/sigma cannot hold, since it has no aggregation, timeframe or near support; the same gap DET0210/T1078.002 was declined for. AN1544 (Linux) is worse: its own mutable element names a 'HostDensityThreshold' — number of unique systems a user authenticates to in a window — which is a count-distinct-by-time query, not a predicate over one event. AN1545 (macOS) asks for 'ProcessTreeDepth' anomaly tracking, again a tree/aggregate property no single unifiedlog event carries. […]

Covered instead by T1078.001, T1078.002, T1078.003.

What the technique is

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence. In some cases, adversaries may abuse inactive accounts: for example, those belonging to individuals who are no longer part of an organization. Using these accounts may allow the adversary to evade detection, as the original account user will not be present to identify any anomalous activity taking place on their account. The overlap of permissions for local, domain, and cloud accounts across a network of systems is of concern because the adversary may be able to pivot across accounts and systems to reach a high level of access (i.e., domain or enterprise administrator) to bypass access controls set within the enterprise.

Read it on attack.mitre.org

What MITRE says you would watch

AN1543
Detection of compromised or misused valid accounts via anomalous logon patterns, abnormal logon types, and inconsistent geographic or time-based activity across Windows endpoints.
AN1544
Detection of valid account misuse through SSH logins, sudo/su abuse, and service account anomalies outside expected patterns.
AN1545
Detection of interactive and remote logins by service accounts or users at unusual times, with unexpected child process activity.