vArmour AppController - SMB Realm Traversal

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

'Detects when SMB traffic crosses Production and Non-Production Realms. Possible network share discovery or lateral tool transfer across realms'

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1135` Network Share Discovery
Lateral Movement	`T1570` Lateral Tool Transfer

Rule body

id: a36de6c3-3198-4d37-92ae-e19e36712c2e
name: vArmour AppController - SMB Realm Traversal
description: |
  'Detects when SMB traffic crosses Production and Non-Production Realms. Possible network share discovery or lateral tool transfer across realms'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: vArmourAC
    dataTypes:
      - CommonSecurityLog
  - connectorId: vArmourACAma
    dataTypes:
      - CommonSecurityLog
  - connectorId: CefAma
    dataTypes:
      - CommonSecurityLog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Discovery
  - LateralMovement
relevantTechniques:
  - T1135
  - T1570
query: |
  CommonSecurityLog
  | where DeviceVendor == "vArmour"
  | where DeviceProduct == "AC"
  | where Activity == "POLICY_VIOLATION"
  | extend PolicyName = extract("(SMB_REALM_TRAVERSAL\\w+{.*})", 1, DeviceCustomString1)
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: DestinationHostName
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIP
version: 1.0.2
kind: Scheduled

Stages and Predicates

Stage 1: `source`

CommonSecurityLog

Stage 2: `where`

| where DeviceVendor == "vArmour"

Stage 3: `where`

| where DeviceProduct == "AC"

Stage 4: `where`

| where Activity == "POLICY_VIOLATION"

Stage 5: `extend`

| extend PolicyName = extract("(SMB_REALM_TRAVERSAL\\w+{.*})", 1, DeviceCustomString1)

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Activity`	eq	`POLICY_VIOLATION`	`field:"Activity" kind:eq value:"POLICY_VIOLATION"`
`DeviceProduct`	eq	`AC`	`field:"DeviceProduct" kind:eq value:"AC"`
`DeviceVendor`	eq	`vArmour`	`field:"DeviceVendor" kind:eq value:"vArmour"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`PolicyName`	`extend`

vArmour AppController - SMB Realm Traversal

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where