Detection rules › Kusto
Cisco WSA - Multiple errors to URL
'Detects multiple connection errors to URL.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1102 Web Service |
Rule body kusto
id: 1db49647-435c-41ad-bf8c-7130ba75429d
name: Cisco WSA - Multiple errors to URL
description: |
'Detects multiple connection errors to URL.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
datatypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1102
query: |
let threshold = 5;
CiscoWSAEvent
| where DvcAction =~ 'NONE'
| summarize count() by SrcUserName, UrlOriginal, bin(TimeGenerated, 5m)
| where count_ >= threshold
| extend URLCustomEntity = UrlOriginal, AccountCustomEntity = SrcUserName
entityMappings:
- entityType: URL
fieldMappings:
- identifier: Url
columnName: URLCustomEntity
- entityType: Account
fieldMappings:
- identifier: Name
columnName: AccountCustomEntity
version: 1.0.2
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 5;
Stage 1: source
CiscoWSAEvent
Stage 2: where
| where DvcAction =~ 'NONE'
Stage 3: summarize
| summarize count() by SrcUserName, UrlOriginal, bin(TimeGenerated, 5m)
Stage 4: where
| where count_ >= threshold
Stage 5: extend
| extend URLCustomEntity = UrlOriginal, AccountCustomEntity = SrcUserName
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.
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 |
|---|---|
SrcUserName | summarize |
UrlOriginal | summarize |
AccountCustomEntity | extend |
URLCustomEntity | extend |