Detection rules › Kusto
Imperva - Multiple user agents from same source
''Detects suspicious number of user agents from the same IP address.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1133 External Remote Services, T1190 Exploit Public-Facing Application |
Rule body kusto
id: 4e8032eb-f04d-4a30-85d3-b74bf2c8f204
name: Imperva - Multiple user agents from same source
description: |
''Detects suspicious number of user agents from the same IP address.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: ImpervaWAFCloudAPI
dataTypes:
- ImpervaWAFCloud
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1190
- T1133
query: |
let threshold = 10;
ImpervaWAFCloud
| summarize d_uas = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)
| where d_uas >= threshold
| extend IPCustomEntity = SrcIpAddr
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPCustomEntity
version: 1.0.0
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 10;
Stage 1: source
ImpervaWAFCloud
Stage 2: summarize
| summarize d_uas = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)
Stage 3: where
| where d_uas >= threshold
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.
| Field | Kind | Values |
|---|---|---|
d_uas | ge |
|
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.
| Field | Source |
|---|---|
SrcIpAddr | summarize |
d_uas | summarize |
IPCustomEntity | extend |