Detection rules › Kusto
Cloudflare - Multiple user agents for single source
'Detects requests with different user agents from one source in short timeframe.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access |
Rule body
id: fc50076a-0275-43d5-b9dd-38346c061f68
name: Cloudflare - Multiple user agents for single source
description: |
'Detects requests with different user agents from one source in short timeframe.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: CloudflareDataConnector
dataTypes:
- Cloudflare
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1190
- T1133
query: |
let threshold = 10;
Cloudflare
| where isnotempty(HttpUserAgentOriginal)
| summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)
| where d_ua > threshold
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SrcIpAddr
version: 1.0.1
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 10;
Stage 1: source
Cloudflare
Stage 2: where
| where isnotempty(HttpUserAgentOriginal)
Stage 3: summarize
| summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)
Stage 4: where
| where d_ua > threshold
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
HttpUserAgentOriginal | is_not_null | field:"HttpUserAgentOriginal" kind:is_not_null | |
d_ua | gt |
| field:"d_ua" kind:gt value:"10" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
SrcIpAddr | summarize |
d_ua | summarize |