Detection rules › Kusto

VMware ESXi - SSH Enable on ESXi Host

Status
available
Severity
high
Time window
10m
Source
github.com/Azure/Azure-Sentinel

'Detects when vim-cmd is used to enable SSH on an ESXi host'

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021 Remote Services

Rule body kusto

id: 4f5b5d79-ff4e-4edd-ae3e-9e1187f0b924
name: VMware ESXi - SSH Enable on ESXi Host
description: |
  'Detects when vim-cmd is used to enable SSH on an ESXi host'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - LateralMovement
relevantTechniques:
  - T1021
query: |
  VMwareESXi
  | where SyslogMessage has_all ("vim-cmd","hostsvc/enable_ssh")
  | extend SrcUsername = extract(@'\[info\]\s+\[(.*?)\]', 1, SyslogMessage)
  | extend DstHostname = extract(@'\[\d+\]\s+\[(.*?)\s+on', 1, SyslogMessage)
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DstHostname
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: SrcUsername
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: source

VMwareESXi

Stage 2: where

| where SyslogMessage has_all ("vim-cmd","hostsvc/enable_ssh")

Stage 3: extend

| extend SrcUsername = extract(@'\[info\]\s+\[(.*?)\]', 1, SyslogMessage)

Stage 4: extend

| extend DstHostname = extract(@'\[\d+\]\s+\[(.*?)\s+on', 1, SyslogMessage)

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
SyslogMessagematch
  • hostsvc/enable_ssh
  • vim-cmd

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

FieldSource
SrcUsernameextend
DstHostnameextend