Detection rules › Kusto

Ping Federate - Unexpected authentication URL.

Status
available
Severity
medium
Time window
14d
Source
github.com/Azure/Azure-Sentinel

'Detects unexpected authentication URL.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: 9578ef7f-cbb4-4e9a-bd26-37c15c53b413
name: Ping Federate - Unexpected authentication URL.
description: |
  'Detects unexpected authentication URL.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CefAma
    dataTypes:
      - CommonSecurityLog
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1078
query: |
  let known_domains = 
  PingFederateEvent
  | where TimeGenerated between (ago(14d) .. (1d))
  | where isnotempty(DeviceCustomString1)
  | extend url_parsed = parse_url(DeviceCustomString1)
  | extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
  | summarize makeset(url_domain);
  PingFederateEvent
  | where isnotempty(DeviceCustomString1)
  | extend url_parsed = parse_url(DeviceCustomString1)
  | extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
  | where url_domain !in (known_domains)
  | extend AccountCustomEntity = DstUserName
  | extend IpCustomEntity = SrcIpAddr
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IpCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Let binding: known_domains used in Stage 5

let known_domains = PingFederateEvent
| where TimeGenerated between (ago(14d) .. (1d))
| where isnotempty(DeviceCustomString1)
| extend url_parsed = parse_url(DeviceCustomString1)
| extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
| summarize makeset(url_domain);

Stage 1: source

PingFederateEvent

Stage 2: where

| where isnotempty(DeviceCustomString1)

Stage 3: extend

| extend url_parsed = parse_url(DeviceCustomString1)

Stage 4: extend

| extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))

Stage 5: where

| where url_domain !in (known_domains)

Stage 6: extend

| extend AccountCustomEntity = DstUserName

Stage 7: extend

| extend IpCustomEntity = SrcIpAddr

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
url_domaineqknown_domainsexcludes:url_domain field:"url_domain" value:"known_domains"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
DeviceCustomString1is_not_null
  • (no value, null check)
field:"DeviceCustomString1" kind:is_not_null

Output fields

These fields are emitted when the rule matches.

FieldSource
url_parsedextend
url_domainextend
AccountCustomEntityextend
IpCustomEntityextend