kevmap

TechniquesT1132.001 › AN0348

AN0348 Analytic 0348

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

<p>ESXi shell (BusyBox) or VMware utilities (openssl, python if present) used to Base64/hex encode data from datastore or config files → followed by abnormal egress from the host (NSX/flow logs) with asymmetric bytes_out or HTTPS posts to non-management endpoints.</p>
Detects
T1132.001 Standard Encoding
Part of
DET0124 Behavior-chain detection for T1132.001 Data Encoding: Standard Encoding (Base64/Hex/MIME) across Windows, Linux, macOS, ESXi

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
esxi:shellcommands containing base64, openssl enc -base64, xxd -pDC0032 Process Creation
esxi:hostdunexpected script/command invocations via hostdDC0038 Application Log Content
NSX:FlowLogsnetwork_flow: bytes_out >> bytes_in to externalDC0078 Network Traffic Flow
NSM:Flowhttp: Base64/MIME looking payloads from ESXi host IPDC0085 Network Traffic Content

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
MgmtCIDRsCIDRs for legitimate vCenter/NSX/backup endpoints.
BytesRatioOut:In ratio deemed suspicious (e.g., ≥3 on ESXi).
TimeWindowCorrelation window between shell command and egress.