kevmap

TechniquesT1132 › AN0303

AN0303 Analytic 0303

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

<p>Custom scripts or processes encode outbound traffic using gzip, Base64, or hex prior to exfiltration via curl, wget, or custom sockets. Encoding typically occurs before or during outbound connections from non-network daemons.</p>
Detects
T1132 Data Encoding
Part of
DET0108 Detection Strategy for Data Encoding in C2 Channels

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
auditd:SYSCALLexecveDC0032 Process Creation
NSM:FlowBase64 strings or gzip in URI, headers, or POST bodyDC0085 Network Traffic Content
linux:syslogUnusual outbound transfers from CLI tools like base64, gzip, or netcatDC0064 Command Execution

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
TimeWindowTune duration of multi-stage encoding + transfer operations to account for script variability
UserContextApply user allow/block list depending on which users normally perform CLI encoding