Detection rules › Kusto
PaloAlto - Dropping or denying session with traffic
'Detects dropping or denying session with traffic.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1133 External Remote Services, T1190 Exploit Public-Facing Application |
Rule body kusto
id: ba663b74-51f4-11ec-bf63-0242ac130002
name: PaloAlto - Dropping or denying session with traffic
description: |
'Detects dropping or denying session with traffic.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: CefAma
dataTypes:
- CommonSecurityLog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1190
- T1133
query: |
let threshold = 100;
PaloAltoCDLEvent
| where EventResourceId =~ 'TRAFFIC'
| where EventResult has_any ("deny", "drop", "reject")
| where tolong(DstBytes) > 0
| where tolong(NetworkPackets) > 0
| summarize count() by SrcIpAddr, DstUsername, bin(TimeGenerated, 10m)
| where count_ > threshold
| extend AccountCustomEntity = DstUsername, IPCustomEntity = SrcIpAddr
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: AccountCustomEntity
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPCustomEntity
version: 1.0.4
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 100;
Stage 1: source
PaloAltoCDLEvent
Stage 2: where
| where EventResourceId =~ 'TRAFFIC'
Stage 3: where
| where EventResult has_any ("deny", "drop", "reject")
Stage 4: where
| where tolong(DstBytes) > 0
Stage 5: where
| where tolong(NetworkPackets) > 0
Stage 6: summarize
| summarize count() by SrcIpAddr, DstUsername, bin(TimeGenerated, 10m)
Stage 7: where
| where count_ > threshold
Stage 8: extend
| extend AccountCustomEntity = DstUsername, 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 |
|---|---|---|
DstBytes | gt |
|
EventResourceId | eq |
|
EventResult | match |
|
NetworkPackets | gt |
|
count_ | gt |
|
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 |
|---|---|
DstUsername | summarize |
SrcIpAddr | summarize |
AccountCustomEntity | extend |
IPCustomEntity | extend |