↳ GitHub sourceAnalytics ruleMedium

Port Scan

Description

'Identifies a source IP scanning multiple open ports on Azure Firewall. This can indicate malicious scanning of ports by an attacker, trying to reveal open ports in the organization that can be compromised for initial access. Configurable Parameters: - Port scan time - the time range to look for multiple ports scanned. Default is set to 30 seconds. - Minimum different ports threshold - alert only if more than this number of ports scanned. Default is set to 100.'
Rule type
Scheduled
Version
1.1.3
Declared status
Available
Query frequency
1d
Query period
1d
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.

let MinimumDifferentPortsThreshold = 100;
let BinTime = 30s;
// Exclude known benign scanner IPs in your environment to reduce noise
let KnownScannerIPs = dynamic([]); 
union isfuzzy=true(
AZFWApplicationRule
| where SourceIp !in (KnownScannerIPs)
| summarize AlertTimedCountPortsInBinTime = dcount(DestinationPort) by SourceIp, bin(TimeGenerated, BinTime), Fqdn
| where AlertTimedCountPortsInBinTime > MinimumDifferentPortsThreshold),
(AZFWNetworkRule
| where SourceIp !in (KnownScannerIPs)
| extend Fqdn = DestinationIp
| summarize AlertTimedCountPortsInBinTime = dcount(DestinationPort) by SourceIp, bin(TimeGenerated, BinTime), Fqdn
| where AlertTimedCountPortsInBinTime > MinimumDifferentPortsThreshold),
(AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog" or OperationName == "AzureFirewallNetworkRuleLog"
| parse msg_s with * "from " SourceIp ":" SourcePort:int " to " Fqdn ":" DestinationPort:int *
| where isnotempty(Fqdn) and isnotempty(SourceIp)
| where SourceIp !in (KnownScannerIPs) 
| summarize AlertTimedCountPortsInBinTime = dcount(DestinationPort) by SourceIp, bin(TimeGenerated, BinTime), Fqdn
| where AlertTimedCountPortsInBinTime > MinimumDifferentPortsThreshold)

Declared entities

IPURL

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
b2c5907b-1040-4692-9802-9946031017e8
Additional source files 2Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Port Scan.yamlsource ↗Solutions/Azure Firewall/Data/Solution_AzureFirewall.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.