Detection rules › Kusto

Cisco Umbrella - URI contains IP address

Severity
medium
Time window
10m
Source
github.com/Azure/Azure-Sentinel

'Malware can use IP address to communicate with C2.'

MITRE ATT&CK coverage

TacticTechniques
Command & ControlNo specific technique

Rule body kusto

id: ee1818ec-5f65-4991-b711-bcf2ab7e36c3
name: Cisco Umbrella - URI contains IP address
description: |
  'Malware can use IP address to communicate with C2.'
severity: Medium
requiredDataConnectors:
  - connectorId: CiscoUmbrellaDataConnector
    dataTypes:
      - Cisco_Umbrella_proxy_CL
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
query: |
  let lbtime = 10m;
  Cisco_Umbrella
  | where TimeGenerated > ago(lbtime)
  | where EventType == 'proxylogs'
  | where DvcAction =~ 'Allowed'
  | where UrlOriginal matches regex @'\Ahttp:\/\/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}.*'
  | project TimeGenerated, SrcIpAddr, Identities
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Identities
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
version: 1.1.1
kind: Scheduled

Stages and Predicates

Parameters

let lbtime = 10m;

Stage 1: source

Cisco_Umbrella

Stage 2: where

| where TimeGenerated > ago(lbtime)

Stage 3: where

| where EventType == 'proxylogs'

Stage 4: where

| where DvcAction =~ 'Allowed'

Stage 5: where

| where UrlOriginal matches regex @'\Ahttp:\/\/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}.*'

Stage 6: project

| project TimeGenerated, SrcIpAddr, Identities

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
DvcActioneq
  • Allowed
EventTypeeq
  • proxylogs transforms: cased
UrlOriginalregex_match
  • \Ahttp:\/\/\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}.*

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
Identitiesproject
SrcIpAddrproject
TimeGeneratedproject