Port Sweep

id: 720335f4-ee8c-4270-9424-d0859222168c
name: Port Sweep
description: |
  'Identifies a source IP scanning same open ports on the Azure Firewall IPs. This can indicate malicious scanning of port by an attacker, trying to reveal IPs with specific ports open in the organization. The ports can be compromised by attackers for initial access, most often by exploiting vulnerability.
  
  Configurable Parameters:
  
  - Port sweep time - the time range to look for multiple hosts scanned. Default is set to 30 seconds.
  - Minimum different hosts threshold - alert only if more than this number of hosts scanned. Default is set to 200.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: AzureFirewall
    dataTypes: 
      - AzureDiagnostics
      - AZFWApplicationRule
      - AZFWNetworkRule
queryFrequency: 1h
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Discovery
  - Reconnaissance
relevantTechniques:
  - T1046
  - T1595.001
query: |
  let MinimumDifferentHostsThreshold = 200;
  let ExcludedPorts = dynamic([80 , 443]);
  let BinTime = 30s;
  union isfuzzy=true(
  AZFWApplicationRule
  | where DestinationPort !in (ExcludedPorts)
  | summarize AlertTimedCountHostsInBinTime = make_set(Fqdn) by SourceIp, bin(TimeGenerated, BinTime), DestinationPort
  | where array_length(AlertTimedCountHostsInBinTime) > MinimumDifferentHostsThreshold
  | mv-expand Fqdn = AlertTimedCountHostsInBinTime),
  (AZFWNetworkRule
  | extend Fqdn = DestinationIp
  | where DestinationPort !in (ExcludedPorts)
  | summarize AlertTimedCountHostsInBinTime = make_set(Fqdn) by SourceIp, bin(TimeGenerated, BinTime), DestinationPort
  | where array_length(AlertTimedCountHostsInBinTime) > MinimumDifferentHostsThreshold
  | mv-expand Fqdn = AlertTimedCountHostsInBinTime),
  (AzureDiagnostics
  | where OperationName == "AzureFirewallApplicationRuleLog" or OperationName == "AzureFirewallNetworkRuleLog"
  | parse msg_s with * "from " SourceIp ":" SourcePort:int " to " Fqdn ":" DestinationPort:int ". " * "Action: " Action "." *
  | where DestinationPort !in (ExcludedPorts)
  | where isnotempty(Fqdn) and isnotempty(SourceIp) and isnotempty(DestinationPort)
  | summarize AlertTimedCountHostsInBinTime = make_set(Fqdn) by SourceIp, bin(TimeGenerated, BinTime), DestinationPort
  | where array_length(AlertTimedCountHostsInBinTime) > MinimumDifferentHostsThreshold
  | mv-expand Fqdn = AlertTimedCountHostsInBinTime)
  | project bin(TimeGenerated, BinTime), SourceIp, DestinationPort, AlertTimedCountHostsInBinTime, Fqdn
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIp
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Fqdn
customDetails:
  DestinationPort: DestinationPort
alertDetailsOverride:
  alertDisplayNameFormat: 'Port Sweep Detected from {{SourceIp}} on Port {{DestinationPort}}'
  alertDescriptionFormat: 'Source IP {{SourceIp}} has scanned {{AlertTimedCountHostsInBinTime}} different hosts on port {{DestinationPort}} within a short time frame, which may indicate reconnaissance activity.'
version: 1.2.3
kind: Scheduled