kevmap

TechniquesT1546.006 › AN0607

AN0607 Analytic 0607

macOS · attack.mitre.org · ATT&CK Enterprise v19.2

<p>Detection focuses on unauthorized modification of Mach-O binaries to include LC_LOAD_DYLIB headers pointing to malicious dylibs. Behavior is identified via a chain of file metadata changes, removal of code signatures, and subsequent anomalous dylib loads at runtime. Correlation of file changes with lack of authorized updates and process memory mapping of unrecognized or unsigned libraries is crucial.</p>
Detects
T1546.006 LC_LOAD_DYLIB Addition
Part of
DET0216 Detection Strategy for LC_LOAD_DYLIB Modification in Mach-O Binaries on macOS

Log sources and channels

Exactly as MITRE states them in x_mitre_log_source_references. Where a channel is vague, it is vague in the source; kevmap does not tidy it.

Log sourceChannelData component
macos:unifiedlogProcess memory maps new dylib (dylib_load event)DC0016 Module Load
macos:unifiedlogMach-O binary modified or LC_LOAD_DYLIB segment insertedDC0061 File Modification
macos:unifiedlogCode signature validation fails or is absent post-binary modificationDC0059 File Metadata

Mutable elements

Parameters MITRE marks as environment-specific. These are the knobs you are expected to tune; they are why an analytic is not a rule.

FieldDescription
TimeWindowCorrelates binary modification and dylib load within a defined time interval (e.g., 1 hour)
DylibPathRegexRegular expression to match known malicious or uncommon library paths
UnsignedDylibThresholdNumber of unsigned or unrecognized dylibs mapped into memory per process
UserContextScope monitoring to non-admin users or sensitive system directories