Detection rules › Kusto

CiscoISE - Command executed with the highest privileges by new user

Status
available
Severity
medium
Time window
5m
Source
github.com/Azure/Azure-Sentinel

'Detects command execution with PrivilegeLevel - 15 by user for wich there was no such activity detected earlier.'

MITRE ATT&CK coverage

Rule body kusto

id: e71890a2-5f61-4790-b1ed-cf1d92d3e398
name: CiscoISE - Command executed with the highest privileges by new user
description: |
  'Detects command execution with PrivilegeLevel - 15 by user for wich there was no such activity detected earlier.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
  - Persistence
  - PrivilegeEscalation
  - DefenseEvasion
  - Execution
relevantTechniques:
  - T1133
  - T1548
  - T1059
query: |
  let lbperiod = 14d;
  let lbtime = 15m;
  let knownPrivUsers =
  CiscoISEEvent
  | where TimeGenerated between (ago(lbperiod) .. ago(lbtime))
  | where PrivilegeLevel == '15'
  | summarize makelist(DstUserName)
  ;
  CiscoISEEvent
  | where TimeGenerated > ago(lbtime)
  | where PrivilegeLevel == '15'
  | where DstUserName !in (knownPrivUsers)
  | project TimeGenerated, SrcIpAddr, DstIpAddr, DstUserName, CmdSet
  | extend AccountCustomEntity = DstUserName
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AccountCustomEntity
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.4
kind: Scheduled

Stages and Predicates

Parameters

let lbperiod = 14d;
let lbtime = 15m;

Let binding: knownPrivUsers

let knownPrivUsers = CiscoISEEvent
| where TimeGenerated between (ago(lbperiod) .. ago(lbtime))
| where PrivilegeLevel == '15'
| summarize makelist(DstUserName);

Derived from lbperiod, lbtime.

Stage 1: source

CiscoISEEvent

Stage 2: where

| where TimeGenerated > ago(lbtime)

Stage 3: where

| where PrivilegeLevel == '15'

Stage 4: where

| where DstUserName !in (knownPrivUsers)

References knownPrivUsers (defined above).

Stage 5: project

| project TimeGenerated, SrcIpAddr, DstIpAddr, DstUserName, CmdSet

Stage 6: extend

| extend AccountCustomEntity = DstUserName

Stage 7: extend

| extend IPCustomEntity = SrcIpAddr

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
DstUserNameeqknownPrivUsers

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
PrivilegeLeveleq
  • 15 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
CmdSetproject
DstIpAddrproject
DstUserNameproject
SrcIpAddrproject
TimeGeneratedproject
AccountCustomEntityextend
IPCustomEntityextend