BitSight - drop in company ratings

Status: available
Severity: high
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

'Rule helps to detect when there is a drop of 10% or more in BitSight company ratings.'

MITRE ATT&CK coverage

Tactic	Techniques
Reconnaissance	`T1591` Gather Victim Org Information
Command & Control	`T1090` Proxy

Rule body

id: d8844f11-3a36-4b97-9062-1e6d57c00e37
name: BitSight - drop in company ratings
description: |
  'Rule helps to detect when there is a drop of 10% or more in BitSight company ratings.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: BitSight
    dataTypes:
      - BitSightGraphData
queryFrequency: 1d
queryPeriod: 24h
triggerOperator: GreaterThan
triggerThreshold: 0
tactics:
  - Reconnaissance
  - CommandAndControl
relevantTechniques:
  - T1591
  - T1090
query: |
    let timeframe = 24h;
    BitSightGraphData
    | where ingestion_time() > ago(timeframe)and toint(RatingDifferance) < 0
    | extend percentage = -(toreal(RatingDifferance)/toreal(Rating))*100
    | where percentage >= 10
    | project RatingDate, Rating, CompanyName, percentage
incidentConfiguration:
    createIncident: false
eventGroupingSettings:
    aggregationKind: AlertPerResult
alertDetailsOverride:
    alertDisplayNameFormat: 'BitSight : Alert for >10% drop in ratings of {{CompanyName}}.'
    alertDescriptionFormat: 'Alert is generated for {{CompanyName}}.\n\nRating Date: {{RatingDate}}\nPercentage Drop: {{percentage}}%'
customDetails:
  CompanyName: CompanyName
  CompanyRating: Rating
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

let timeframe = 24h;

Stage 1: `source`

BitSightGraphData

Stage 2: `where`

| where ingestion_time() > ago(timeframe)and toint(RatingDifferance) < 0

Stage 3: `extend`

| extend percentage = -(toreal(RatingDifferance)/toreal(Rating))*100

Stage 4: `where`

| where percentage >= 10

Stage 5: `project`

| project RatingDate, Rating, CompanyName, percentage

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`RatingDifferance`	lt	`0` transforms: `toint`	`field:"RatingDifferance" kind:lt value:"0"`
`percentage`	ge	`10`	`field:"percentage" kind:ge value:"10"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`CompanyName`	`project`
`Rating`	`project`
`RatingDate`	`project`
`percentage`	`project`

BitSight - drop in company ratings

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: where

Stage 5: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `where`

Stage 5: `project`