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Vectra AI Detect - Suspected Compromised Host

Description

'Create an incident when a Host is suspected to be compromised. The higher the severity level is, the more immediate attention it requires as Vectra AI engine is more confident that this is a real threat. Level of severity are: Low, Medium, High, Critical). Recommended configuration is to trigger an alert for at least High and Critical.'
Rule type
Scheduled
Version
1.0.9
Declared status
Available
Query frequency
5m
Query period
5m
Trigger
gt 0

Declared MITRE coverage

Declared sources

Metadata from the source file. No dependencies inferred from KQL.

Connectors

Data types

KQL query

Original query, unchanged.

// Edit this variable to only keep the Severity level where an incident needs to be created (Defaults are: "High", "Critical" ). Possible values are: "Low", "Medium", "High", "Critical"
let configured_level = dynamic(["High", "Critical"]);
CommonSecurityLog
| where DeviceVendor == "Vectra Networks"
| where DeviceProduct == "X Series"
| where DeviceEventClassID == "hsc"
| project-rename threat_score = FlexNumber1
| project-rename certainty_score = FlexNumber2
| project-rename vectra_URL = DeviceCustomString4
| project-rename detection_name = DeviceEventClassID
| project-rename score_decreases = DeviceCustomString3
| extend level = case( threat_score <  50 and certainty_score < 50, "Low",
                      threat_score < 50 and certainty_score >= 50 , "Medium", 
                      threat_score >= 50 and certainty_score <= 50, "High", 
                      threat_score >= 50 and certainty_score >= 50, "Critical",
                      "UNKNOWN")
| extend Severity = case(level == "Info", "Informational",level == "Critical", "High", level)
| where level in (configured_level) 
//keep only the event with the highest threat score per Host
| summarize arg_max(TimeGenerated, *) by SourceHostName
| sort by TimeGenerated

Declared entities

Host

Related content

Links established from declared identifiers and solution manifests.

Source provenance

GitHub

Displayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.

Source identifier
60eb6cf0-3fa1-44c1-b1fe-220fbee23d63
Additional source files 2Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-Host-by-Severity.yamlsource ↗Solutions/Vectra AI Detect/Data/Solution_Vectra AI Detect.jsonsolution-membership ↗
GSTEP / CATALOG TRACKING

Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC

GSTEP sync dates, separate from the source content’s publication dates.