Detection rules › Kusto
Excessive Denied Proxy Traffic
'This alert creates an incident when a client generates an excessive amounts of denied proxy traffic.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1562 Impair Defenses |
| Command & Control | T1090 Proxy |
Rule body kusto
id: 7a58b253-0ef2-4248-b4e5-c350f15a8346
name: Excessive Denied Proxy Traffic
description: |
'This alert creates an incident when a client generates an excessive amounts of denied proxy traffic.'
severity: Low
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
datatypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- DefenseEvasion
- CommandAndControl
relevantTechniques:
- T1090
- T1562
query: |
let threshold = 100;
SymantecProxySG
| where sc_filter_result =~ "DENIED"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by c_ip, cs_host
| where count_ > threshold
entityMappings:
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: cs_host
- entityType: IP
fieldMappings:
- identifier: Address
columnName: c_ip
version: 1.0.5
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 100;
Stage 1: source
SymantecProxySG
Stage 2: where
| where sc_filter_result =~ "DENIED"
Stage 3: summarize
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by c_ip, cs_host
Stage 4: where
| where count_ > threshold
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 |
|---|---|---|
count_ | gt |
|
sc_filter_result | eq |
|
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 |
|---|---|
EndTime | summarize |
StartTime | summarize |
c_ip | summarize |
cs_host | summarize |