Data Encrypted for Impact
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 may encrypt files stored on a mobile device to prevent the user from accessing them. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key (ransomware) or to render data permanently inaccessible in cases where the key is not saved or transmitted.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1781
An application with access to broad file scopes or sensitive storage areas becomes active, performs abnormal burst file reads and writes across many user or shared-storage locations, transforms file content or extensions at scale in a short window, and causes rapid file inaccessibility, rewrite, or replacement inconsistent with normal sync, backup, media processing, or document-editing behavior. The defender correlates capability state, app lifecycle, framework use, bulk file-write effects, and optional network communications to distinguish encrypt-for-impact behavior from benign bulk file operations.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.