Detection rules › Kusto
Excessive Blocked Traffic Events Generated by User
'Creates an incident when a Symantec Endpoint Proection agent detects excessive amounts of blocked traffic generated by a single user.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Lateral Movement | T1021 Remote Services |
| Command & Control | T1001 Data Obfuscation, T1132 Data Encoding |
| Exfiltration | T1041 Exfiltration Over C2 Channel |
Rule body kusto
id: fa0ab69c-7124-4f62-acdd-61017cf6ce89
name: Excessive Blocked Traffic Events Generated by User
description: |
'Creates an incident when a Symantec Endpoint Proection agent detects excessive amounts of blocked traffic generated by a single user.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
datatypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- Exfiltration
- CommandAndControl
- LateralMovement
relevantTechniques:
- T1041
- T1132
- T1001
- T1021
query: |
let threshold = 15;
let NoteableEvents = SymantecEndpointProtection
| where LogType == "Agent Traffic Logs"
| where Action =~ "Blocked"
| summarize TotalBlockedEvents = count() by UserName
| where TotalBlockedEvents > threshold;
SymantecEndpointProtection
| where LogType =~ "Agent Traffic Logs"
| where Action =~ "Blocked"
| join kind=inner (NoteableEvents) on UserName
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by UserName, RuleName, ServerName, LocalHostIpAddr, LocalPortNumber, TrafficDirection, RemoteHostIpAddr, RemotePortNumber, ApplicationName
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: UserName
- entityType: IP
fieldMappings:
- identifier: Address
columnName: LocalHostIpAddr
- entityType: IP
fieldMappings:
- identifier: Address
columnName: RemoteHostIpAddr
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: ServerName
version: 1.0.3
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 15;
Let binding: NoteableEvents
let NoteableEvents = SymantecEndpointProtection
| where LogType == "Agent Traffic Logs"
| where Action =~ "Blocked"
| summarize TotalBlockedEvents = count() by UserName
| where TotalBlockedEvents > threshold;
Derived from threshold.
Stage 1: source
SymantecEndpointProtection
Stage 2: where
| where LogType =~ "Agent Traffic Logs"
Stage 3: where
| where Action =~ "Blocked"
Stage 4: join
| join kind=inner (NoteableEvents) on UserName
Stage 5: summarize
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by UserName, RuleName, ServerName, LocalHostIpAddr, LocalPortNumber, TrafficDirection, RemoteHostIpAddr, RemotePortNumber, ApplicationName
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 |
|---|---|---|
Action | eq |
|
LogType | eq |
|
TotalBlockedEvents | 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 |
|---|---|
ApplicationName | summarize |
EndTimeUtc | summarize |
LocalHostIpAddr | summarize |
LocalPortNumber | summarize |
RemoteHostIpAddr | summarize |
RemotePortNumber | summarize |
RuleName | summarize |
ServerName | summarize |
StartTimeUtc | summarize |
Total | summarize |
TrafficDirection | summarize |
UserName | summarize |