Port Sweep

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Id	720335f4-ee8c-4270-9424-d0859222168c
Rulename	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
Tactics	Discovery
Techniques	T1046
Required data connectors	AzureFirewall
Kind	Scheduled
Query frequency	1h
Query period	1d
Trigger threshold	1
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Port Sweep.yaml
Version	1.2.2
Arm template	720335f4-ee8c-4270-9424-d0859222168c.json

KQL

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

YAML

id: 720335f4-ee8c-4270-9424-d0859222168c
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  
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.'  
requiredDataConnectors:
- connectorId: AzureFirewall
  dataTypes:
  - AzureDiagnostics
  - AZFWApplicationRule
  - AZFWNetworkRule
tactics:
- Discovery
status: Available
queryFrequency: 1h
queryPeriod: 1d
triggerOperator: gt
kind: Scheduled
name: Port Sweep
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Port Sweep.yaml
version: 1.2.2
relevantTechniques:
- T1046
severity: Medium
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: SourceIp
  entityType: IP
- fieldMappings:
  - identifier: Url
    columnName: Fqdn
  entityType: URL
triggerThreshold: 1

ARM