kevmap

TechniquesT1027.003 › AN0331

AN0331 Analytic 0331

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

<p>Detects execution of image viewers or PowerShell scripts accessing or decoding files with mismatched MIME headers or embedded script-like byte patterns; often correlated with suspicious parent-child process lineage and outbound connections.</p>
Detects
T1027.003 Steganography
Part of
DET0119 Detection Strategy for Steganographic Abuse in File & Script Execution

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
WinEventLog:SysmonEventCode=1DC0032 Process Creation
WinEventLog:SysmonEventCode=3, 22DC0082 Network Connection Creation
WinEventLog:SecurityEventCode=4663, 4670, 4656DC0055 File Access

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
ParentProcessImageTune to identify image editors/viewers invoking script interpreters (e.g., `mspaint.exe` > `powershell.exe`)
MimeHeaderMismatchToleranceAdjust tolerance for image file headers that do not match file extensions or content structure
TimeWindowDefine the temporal range to correlate decoding → execution → network beaconing