T1461Not expressible in SigmaMOBILE

Lockscreen Bypass

Initial AccessAndroid, iOS

Where this stands

No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.

Sigma has no logsource taxonomy for mobile platforms. MITRE's telemetry here is mobile EDR and device APIs, which no Sigma rule can address.

What the technique is

An adversary with physical access to a mobile device may seek to bypass the device’s lockscreen. Several methods exist to accomplish this, including: Biometric spoofing: If biometric authentication is used, an adversary could attempt to spoof a mobile device’s biometric authentication mechanism. Both iOS and Android partly mitigate this attack by requiring the device’s passcode rather than biometrics to unlock the device after every device restart, and after a set or random amount of time. Unlock code bypass: An adversary could attempt to brute-force or otherwise guess the lockscreen passcode (typically a PIN or password), including physically observing (“shoulder surfing”) the device owner’s use of the lockscreen passcode. Mobile OS vendors partly mitigate this by implementing incremental backoff timers after a set number of failed unlock attempts, as well as a configurable full device wipe after several failed unlock attempts. Vulnerability exploit: Techniques have been periodically demonstrated that exploit mobile devices to bypass the lockscreen. The vulnerabilities are generally patched by the device or OS vendor once disclosed.

Read it on attack.mitre.org

What MITRE says you would watch

AN1723
A lock-state transition telemetry, special access or privileged interaction capability, security-sensitive framework use, and immediate downstream activity while the user-interaction context is weak or inconsistent. This yields stronger coverage on Android than iOS.
AN1724
Defender correlates an iOS-specific reduced-confidence chain where a supervised or managed device transitions from locked or inactive state to interactive or application-active state with weak evidence of expected user authentication, often accompanied by abnormal protected posture change, trust-state change, unexpected app wake, sensor use, or immediate downstream communication. Because direct visibility into lockscreen bypass mechanics on iOS is limited, the analytic prioritizes strong device-state effects and post-unlock behavior rather than pretending to observe the exact bypass method.