Detection of System Information Discovery

ID: DET0601
Domains: Mobile
Analytics: AN1648, AN1649
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1648

Defender correlates an app process performing a burst of OS/device attribute lookups (build, hardware, SDK level, system properties) with near-term execution branching (feature gating, module load, permission workflow changes) and/or immediate outbound communications, indicating environment evaluation used to shape follow-on actions.

Log Sources
Data Component Name Channel
OS API Execution (DC0021) android:logcat Application accesses android.os.Build fields or device configuration APIs (MODEL, MANUFACTURER, VERSION.SDK_INT, HARDWARE)
Mutable Elements
Field Description
TimeWindowSeconds Correlation window for system-info collection burst → outbound transmission (e.g., 60–900s).
MinSystemInfoSignals Minimum number of distinct system-attribute reads/queries within window to count as ‘broad fingerprinting’ (tune to telemetry fidelity).
DistinctAttributeThreshold How many distinct attribute categories (build fields, cpu, locale, patch level, network identifiers) must be observed.
BackgroundOnly If true, require the burst occurs while app is background to reduce noise from legitimate settings/about-device screens.
AllowlistedPackages Legitimate device management, diagnostics, carrier services, and enterprise security apps expected to collect device inventory.
NewDomainWindowSeconds Window for ‘newly contacted domain’ enrichment after fingerprinting burst.
SmallPostByteRange Approximate payload size range used for ‘fingerprint submit’ heuristic (environment dependent).

AN1649

Defender correlates an app querying device model and iOS version (often limited to UIDevice-visible attributes) with subsequent behavior divergence (capability gating, alternate code paths) and/or near-term outbound connections, suggesting device fingerprinting for decision-making rather than normal telemetry.

Log Sources
Data Component Name Channel
OS API Execution (DC0021) iOS:unifiedlog Application invokes UIDevice queries (model, systemVersion, name)
Mutable Elements
Field Description
QueryFrequencyThreshold Baseline-dependent threshold for distinguishing normal app telemetry from discovery behavior
QueryToExecutionDeviationWindow Defines acceptable delay between device queries and execution changes
DeviceModelBaseline Allows tuning for environments with homogeneous vs heterogeneous device fleets