Detection rules › Kusto

ProofpointPOD - Weak ciphers

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

'Detects when weak TLS ciphers are used.'

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1573 Encrypted Channel

Rule body kusto

id: 56b0a0cd-894e-4b38-a0a1-c41d9f96649a
name: ProofpointPOD - Weak ciphers
description: |
  'Detects when weak TLS ciphers are used.'
severity: Low
status: Available 
requiredDataConnectors:
  - connectorId: ProofpointPOD
    dataTypes:
      - ProofpointPOD_message_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1573
query: |
  let lbtime = 1h;
  let tls_ciphers = dynamic(['RC4-SHA', 'DES-CBC3-SHA']);
  ProofpointPOD
  | where EventType == 'message'
  | where TlsCipher in (tls_ciphers)
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Parameters

let lbtime = 1h;
let tls_ciphers = dynamic(['RC4-SHA', 'DES-CBC3-SHA']);

Stage 1: source

ProofpointPOD

Stage 2: where

| where EventType == 'message'

Stage 3: where

| where TlsCipher in (tls_ciphers)

Stage 4: extend

| extend IPCustomEntity = SrcIpAddr

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
EventTypeeq
  • message transforms: cased
TlsCipherin
  • DES-CBC3-SHA transforms: cased
  • RC4-SHA 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
IPCustomEntityextend