Detection rules › Kusto

Cisco WSA - Internet access from public IP

Status
available
Severity
medium
Time window
1h
Source
github.com/Azure/Azure-Sentinel

'Detects internet access from public IP.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: 4250b050-e1c6-4926-af04-9484bbd7e94f
name: Cisco WSA - Internet access from public IP
description: |
  'Detects internet access from public IP.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1189
query: |
  let ip_except = dynamic(['127.0.0.2']);    //Add exceptions to this list
  CiscoWSAEvent
  | where ipv4_is_private(SrcIpAddr) == false
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

let ip_except = dynamic(['127.0.0.2']);

Stage 1: source

CiscoWSAEvent

Stage 2: where

| where ipv4_is_private(SrcIpAddr) == false

Stage 3: extend

| extend IPCustomEntity = SrcIpAddr

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
SrcIpAddrcidr_match10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16, 127.0.0.0/8excludes:SrcIpAddr

Output fields

These fields are emitted when the rule matches.

FieldSource
IPCustomEntityextend