Detection rules › Kusto

CiscoISE - Device PostureStatus changed to non-compliant

Status
available
Severity
medium
Time window
15m
Source
github.com/Azure/Azure-Sentinel

'Detects when device changes PostureStatus from "Compliant".'

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1098 Account Manipulation
Privilege EscalationT1098 Account Manipulation

Rule body kusto

id: 548a2eda-d3eb-46cc-8d4b-1601551629e4
name: CiscoISE - Device PostureStatus changed to non-compliant
description: |
  'Detects when device changes PostureStatus from "Compliant".'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 15m
queryPeriod: 15m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
  - Persistence
relevantTechniques:
  - T1098
query: |
  let lbtime_48h = 48h;
  let lbtime_24h = 24h;
  let lbtime_now = now();
  let compliantIPs = CiscoISEEvent
  | where TimeGenerated between (ago(lbtime_48h) .. ago(lbtime_24h))
  | where PostureStatus == 'Compliant'
  | summarize makelist(DstIpAddr)
  ;
  CiscoISEEvent
  | where TimeGenerated between (ago(lbtime_24h) .. lbtime_now)
  | where PostureStatus != 'Compliant'
  | where DstIpAddr in (compliantIPs)
  | project DstIpAddr
  | extend IPCustomEntity = DstIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Parameters

let lbtime_48h = 48h;
let lbtime_24h = 24h;
let lbtime_now = now();

Let binding: compliantIPs

let compliantIPs = CiscoISEEvent
| where TimeGenerated between (ago(lbtime_48h) .. ago(lbtime_24h))
| where PostureStatus == 'Compliant'
| summarize makelist(DstIpAddr);

Derived from lbtime_48h, lbtime_24h.

Stage 1: source

CiscoISEEvent

Stage 2: where

| where TimeGenerated between (ago(lbtime_24h) .. lbtime_now)

Stage 3: where

| where PostureStatus != 'Compliant'

Stage 4: where

| where DstIpAddr in (compliantIPs)

References compliantIPs (defined above).

Stage 5: project

| project DstIpAddr

Stage 6: extend

| extend IPCustomEntity = DstIpAddr

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
DstIpAddrin
  • compliantIPs transforms: cased
PostureStatusne
  • Compliant transforms: cased

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
DstIpAddrproject
IPCustomEntityextend