Detection rules › Kusto

Cisco SEG - Possible outbreak

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

'Detects possible outbreak activity.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: 53242559-95ea-4d4c-b003-107e8f06304b
name: Cisco SEG - Possible outbreak
description: |
  'Detects possible outbreak activity.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CefAma
    dataTypes:
      - CommonSecurityLog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1566
query: |
  CiscoSEGEvent
  | where NetworkDirection =~ 'Incoming'
  | where tostring(AdditionalFields) has 'ESAOFVerdict'
  | extend of_verdict = extract(@'ESAOFVerdict":"(NOT_EVALUATED|POSITIVE|NEGATIVE)"', 1, tostring(AdditionalFields))
  | where of_verdict =~ 'POSITIVE'
  | extend AccountCustomEntity = DstUserName
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Stage 1: source

CiscoSEGEvent

Stage 2: where

| where NetworkDirection =~ 'Incoming'

Stage 3: where

| where tostring(AdditionalFields) has 'ESAOFVerdict'

Stage 4: extend

| extend of_verdict = extract(@'ESAOFVerdict":"(NOT_EVALUATED|POSITIVE|NEGATIVE)"', 1, tostring(AdditionalFields))

Stage 5: where

| where of_verdict =~ 'POSITIVE'

Stage 6: extend

| extend AccountCustomEntity = DstUserName

Indicators

These rows show field, operator, and value matches.

Output fields

These fields are emitted when the rule matches.

FieldSource
of_verdictextend
AccountCustomEntityextend