kevmap

TechniquesT1573.001 › AN0401

AN0401 Analytic 0401

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

<p>Unexpected processes (e.g., bash, python, custom binaries) dynamically loading libcrypto or performing AES/RC4 encryption operations, then initiating outbound sessions with abnormal byte entropy or asymmetric traffic patterns.</p>
Detects
T1573.001 Symmetric Cryptography
Part of
DET0143 Detection Strategy for Encrypted Channel via Symmetric Cryptography 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 or socket/connect system calls from processes using crypto librariesDC0032 Process Creation
linux:syslogSystem daemons initiating encrypted sessions with unexpected destinationsDC0038 Application Log Content
linux:osqueryProcess linked with libcrypto.so making external connectionsDC0016 Module Load

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
TrustedCryptoLibsBaseline expected crypto libraries to suppress false positives.
TrafficAsymmetryRatioRatio of sent/received bytes indicating possible hidden C2.

KEV CVEs whose mapped technique this analytic detects

CVEVendor / productState
CVE-2021-40449Microsoft WindowsMapped
CVE-2021-40539Zoho ManageEngineMapped
CVE-2021-44077Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter PlusMapped