Archive Collected Data
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
Adversaries may compress and/or encrypt data that is collected prior to exfiltration. Compressing data can help to obfuscate its contents and minimize use of network resources. Encryption can be used to hide information that is being exfiltrated from detection or make exfiltration less conspicuous upon inspection by a defender. Both compression and encryption are done prior to exfiltration, and can be performed using a utility, programming library, or custom algorithm.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1767
The defender correlates recent access to locally collected or protected data with subsequent compression, packaging, or encryption behavior inside the same app context, followed by creation of archive-like or high-entropy output and optional near-term network transmission. The analytic prioritizes Android runtime and storage effects: application data access or sensor-derived collection, compression/encryption framework use, archive/blob creation in app-accessible storage, and background or device-locked execution inconsistent with the app’s declared function.
- AN1768
The defender correlates managed-app data access and lifecycle context with indirect evidence of packaging or encryption prior to outbound transfer. Because direct archive/compression visibility is generally weaker on iOS, the analytic anchors on app lifecycle state, file/output effects observable by mobile EDR where available, managed app role via MDM, and downstream network uploads that closely follow creation of new large or high-entropy local artifacts. Confidence is lower when only network effects are available.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.