Detection rules › Kusto

PulseConnectSecure - Potential Brute Force Attempts

Status
available
Severity
low
Time window
1h
Group by
Source_IP, User
Source
github.com/Azure/Azure-Sentinel

'This query identifies evidence of potential brute force attack by looking at multiple failed attempts to log into the VPN server'

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1110 Brute Force

Rule body kusto

id: 34663177-8abf-4db1-b0a4-5683ab273f44
name: PulseConnectSecure - Potential Brute Force Attempts
description: |
  'This query identifies evidence of potential brute force attack by looking at multiple failed attempts to log into the VPN server'
severity: Low
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
query: |
  let threshold = 20;
  PulseConnectSecure
  | where Messages contains "Login failed"
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by User, Source_IP
  | where count_ > threshold
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: User
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: Source_IP
version: 1.0.4
kind: Scheduled

Stages and Predicates

Parameters

let threshold = 20;

Stage 1: source

PulseConnectSecure

Stage 2: where

| where Messages contains "Login failed"

Stage 3: summarize

| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by User, Source_IP

Stage 4: where

| where count_ > threshold

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
Messagescontains
  • Login failed
count_gt
  • 20 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
EndTimesummarize
Source_IPsummarize
StartTimesummarize
Usersummarize