Detection rules › Kusto

Cisco WSA - Unscannable file or scan error

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

'Detects unscanned downloaded file.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: 9b61a945-ebcb-4245-b6e4-51f3addb5248
name: Cisco WSA - Unscannable file or scan error
description: |
  'Detects unscanned downloaded file.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1189
query: |
  CiscoWSAEvent
  | where isnotempty(AmpFileName)
  | where AmpScanningVerdict in ('2', '3')
  | extend IPCustomEntity = SrcIpAddr, FileCustomEntity = AmpFileName, AccountCustomEntity = SrcUserName
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
  - entityType: File
    fieldMappings:
      - identifier: Name
        columnName: FileCustomEntity
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Stage 1: source

CiscoWSAEvent

Stage 2: where

| where isnotempty(AmpFileName)

Stage 3: where

| where AmpScanningVerdict in ('2', '3')

Stage 4: extend

| extend IPCustomEntity = SrcIpAddr, FileCustomEntity = AmpFileName, AccountCustomEntity = SrcUserName

Indicators

These rows show field, operator, and value matches.

Output fields

These fields are emitted when the rule matches.

FieldSource
AccountCustomEntityextend
FileCustomEntityextend
IPCustomEntityextend