kevmap

TechniquesT1566.003 › AN0321

AN0321 Analytic 0321

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

<p>Use of non-enterprise email or messaging services in Thunderbird, Evolution, or browsers leading to suspicious file downloads and subsequent execution. Defender view includes browser-initiated downloads of unexpected content and shell or interpreter processes launched post-download.</p>
Detects
T1566.003 Spearphishing via Service
Part of
DET0115 Detection Strategy for Spearphishing via a Service across OS Platforms

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:SYSCALLexecve: Execution of bash, python, or perl processes spawned by browser/email clientDC0032 Process Creation
linux:syslogInbound messages from webmail services containing attachments or URLsDC0038 Application Log Content
NSM:FlowOutbound traffic to domains/IPs not previously resolved, occurring shortly after attachment download or link clickDC0078 Network Traffic Flow

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
BrowserProcessesConfigured list of browsers or email clients to monitor (e.g., firefox, chromium, thunderbird).
PhishingIndicatorsCustom regex rules for suspicious URL patterns, file extensions, or encoded links.