High count of connections by client IP on many ports

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Id	44a555d8-ecee-4a25-95ce-055879b4b14b
Rulename	High count of connections by client IP on many ports
Description	Identifies when 30 or more ports are used for a given client IP in 10 minutes occurring on the IIS server. This could be indicative of attempted port scanning or exploit attempt at internet facing web applications. This could also simply indicate a misconfigured service or device. References: IIS status code mapping - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0 Win32 Status code mapping - https://msdn.microsoft.com/library/cc231199.aspx
Severity	Medium
Tactics	InitialAccess
Techniques	T1190
Required data connectors	AzureMonitor(IIS)
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/W3CIISLog/HighPortCountByClientIP.yaml
Version	1.0.3
Arm template	44a555d8-ecee-4a25-95ce-055879b4b14b.json

KQL

let timeBin = 10m;
let portThreshold = 30;
W3CIISLog
| extend scStatusFull = strcat(scStatus, ".",scSubStatus)
// Map common IIS codes
| extend scStatusFull_Friendly = case(
scStatusFull == "401.0", "Access denied.",
scStatusFull == "401.1", "Logon failed.",
scStatusFull == "401.2", "Logon failed due to server configuration.",
scStatusFull == "401.3", "Unauthorized due to ACL on resource.",
scStatusFull == "401.4", "Authorization failed by filter.",
scStatusFull == "401.5", "Authorization failed by ISAPI/CGI application.",
scStatusFull == "403.0", "Forbidden.",
scStatusFull == "403.4", "SSL required.",
"See - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0")
// Mapping to Hex so can be mapped using website in comments above
| extend scWin32Status_Hex = tohex(tolong(scWin32Status))
// Map common win32 codes
| extend scWin32Status_Friendly = case(
scWin32Status_Hex =~ "775", "The referenced account is currently locked out and cannot be logged on to.",
scWin32Status_Hex =~ "52e", "Logon failure: Unknown user name or bad password.",
scWin32Status_Hex =~ "532", "Logon failure: The specified account password has expired.",
scWin32Status_Hex =~ "533", "Logon failure: Account currently disabled.",
scWin32Status_Hex =~ "2ee2", "The request has timed out.",
scWin32Status_Hex =~ "0", "The operation completed successfully.",
scWin32Status_Hex =~ "1", "Incorrect function.",
scWin32Status_Hex =~ "2", "The system cannot find the file specified.",
scWin32Status_Hex =~ "3", "The system cannot find the path specified.",
scWin32Status_Hex =~ "4", "The system cannot open the file.",
scWin32Status_Hex =~ "5", "Access is denied.",
scWin32Status_Hex =~ "8009030e", "SEC_E_NO_CREDENTIALS",
scWin32Status_Hex =~ "8009030C", "SEC_E_LOGON_DENIED",
"See - https://msdn.microsoft.com/library/cc231199.aspx")
// decode URI when available
| extend decodedUriQuery = url_decode(csUriQuery)
// Count of attempts by client IP on many ports
| summarize makeset(sPort), makeset(decodedUriQuery), makeset(csUserName), makeset(sSiteName), makeset(sPort), makeset(csUserAgent), makeset(csMethod), makeset(csUriQuery), makeset(scStatusFull), makeset(scStatusFull_Friendly), makeset(scWin32Status_Hex), makeset(scWin32Status_Friendly), ConnectionsCount = count() by bin(TimeGenerated, timeBin), cIP, Computer, sIP
| extend portCount = arraylength(set_sPort)
| where portCount >= portThreshold
| project TimeGenerated, cIP, set_sPort, set_csUserName, set_decodedUriQuery, Computer, set_sSiteName, sIP, set_csUserAgent, set_csMethod, set_scStatusFull, set_scStatusFull_Friendly, set_scWin32Status_Hex, set_scWin32Status_Friendly, ConnectionsCount, portCount
| order by portCount

YAML

query: |
  let timeBin = 10m;
  let portThreshold = 30;
  W3CIISLog
  | extend scStatusFull = strcat(scStatus, ".",scSubStatus)
  // Map common IIS codes
  | extend scStatusFull_Friendly = case(
  scStatusFull == "401.0", "Access denied.",
  scStatusFull == "401.1", "Logon failed.",
  scStatusFull == "401.2", "Logon failed due to server configuration.",
  scStatusFull == "401.3", "Unauthorized due to ACL on resource.",
  scStatusFull == "401.4", "Authorization failed by filter.",
  scStatusFull == "401.5", "Authorization failed by ISAPI/CGI application.",
  scStatusFull == "403.0", "Forbidden.",
  scStatusFull == "403.4", "SSL required.",
  "See - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0")
  // Mapping to Hex so can be mapped using website in comments above
  | extend scWin32Status_Hex = tohex(tolong(scWin32Status))
  // Map common win32 codes
  | extend scWin32Status_Friendly = case(
  scWin32Status_Hex =~ "775", "The referenced account is currently locked out and cannot be logged on to.",
  scWin32Status_Hex =~ "52e", "Logon failure: Unknown user name or bad password.",
  scWin32Status_Hex =~ "532", "Logon failure: The specified account password has expired.",
  scWin32Status_Hex =~ "533", "Logon failure: Account currently disabled.",
  scWin32Status_Hex =~ "2ee2", "The request has timed out.",
  scWin32Status_Hex =~ "0", "The operation completed successfully.",
  scWin32Status_Hex =~ "1", "Incorrect function.",
  scWin32Status_Hex =~ "2", "The system cannot find the file specified.",
  scWin32Status_Hex =~ "3", "The system cannot find the path specified.",
  scWin32Status_Hex =~ "4", "The system cannot open the file.",
  scWin32Status_Hex =~ "5", "Access is denied.",
  scWin32Status_Hex =~ "8009030e", "SEC_E_NO_CREDENTIALS",
  scWin32Status_Hex =~ "8009030C", "SEC_E_LOGON_DENIED",
  "See - https://msdn.microsoft.com/library/cc231199.aspx")
  // decode URI when available
  | extend decodedUriQuery = url_decode(csUriQuery)
  // Count of attempts by client IP on many ports
  | summarize makeset(sPort), makeset(decodedUriQuery), makeset(csUserName), makeset(sSiteName), makeset(sPort), makeset(csUserAgent), makeset(csMethod), makeset(csUriQuery), makeset(scStatusFull), makeset(scStatusFull_Friendly), makeset(scWin32Status_Hex), makeset(scWin32Status_Friendly), ConnectionsCount = count() by bin(TimeGenerated, timeBin), cIP, Computer, sIP
  | extend portCount = arraylength(set_sPort)
  | where portCount >= portThreshold
  | project TimeGenerated, cIP, set_sPort, set_csUserName, set_decodedUriQuery, Computer, set_sSiteName, sIP, set_csUserAgent, set_csMethod, set_scStatusFull, set_scStatusFull_Friendly, set_scWin32Status_Hex, set_scWin32Status_Friendly, ConnectionsCount, portCount
  | order by portCount  
name: High count of connections by client IP on many ports
requiredDataConnectors:
- connectorId: AzureMonitor(IIS)
  dataTypes:
  - W3CIISLog
entityMappings:
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: cIP
description: |
  'Identifies when 30 or more ports are used for a given client IP in 10 minutes occurring on the IIS server.
  This could be indicative of attempted port scanning or exploit attempt at internet facing web applications.
  This could also simply indicate a misconfigured service or device.
  References:
  IIS status code mapping - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0
  Win32 Status code mapping - https://msdn.microsoft.com/library/cc231199.aspx'  
kind: Scheduled
severity: Medium
triggerThreshold: 0
queryPeriod: 1d
queryFrequency: 1d
triggerOperator: gt
metadata:
  author:
    name: Microsoft Security Research
  source:
    kind: Community
  categories:
    domains:
    - Security - Network
  support:
    tier: Community
tactics:
- InitialAccess
relevantTechniques:
- T1190
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/W3CIISLog/HighPortCountByClientIP.yaml
id: 44a555d8-ecee-4a25-95ce-055879b4b14b
version: 1.0.3

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/44a555d8-ecee-4a25-95ce-055879b4b14b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/44a555d8-ecee-4a25-95ce-055879b4b14b')]",
      "properties": {
        "alertRuleTemplateName": "44a555d8-ecee-4a25-95ce-055879b4b14b",
        "customDetails": null,
        "description": "'Identifies when 30 or more ports are used for a given client IP in 10 minutes occurring on the IIS server.\nThis could be indicative of attempted port scanning or exploit attempt at internet facing web applications.\nThis could also simply indicate a misconfigured service or device.\nReferences:\nIIS status code mapping - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0\nWin32 Status code mapping - https://msdn.microsoft.com/library/cc231199.aspx'\n",
        "displayName": "High count of connections by client IP on many ports",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "cIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/W3CIISLog/HighPortCountByClientIP.yaml",
        "query": "let timeBin = 10m;\nlet portThreshold = 30;\nW3CIISLog\n| extend scStatusFull = strcat(scStatus, \".\",scSubStatus)\n// Map common IIS codes\n| extend scStatusFull_Friendly = case(\nscStatusFull == \"401.0\", \"Access denied.\",\nscStatusFull == \"401.1\", \"Logon failed.\",\nscStatusFull == \"401.2\", \"Logon failed due to server configuration.\",\nscStatusFull == \"401.3\", \"Unauthorized due to ACL on resource.\",\nscStatusFull == \"401.4\", \"Authorization failed by filter.\",\nscStatusFull == \"401.5\", \"Authorization failed by ISAPI/CGI application.\",\nscStatusFull == \"403.0\", \"Forbidden.\",\nscStatusFull == \"403.4\", \"SSL required.\",\n\"See - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0\")\n// Mapping to Hex so can be mapped using website in comments above\n| extend scWin32Status_Hex = tohex(tolong(scWin32Status))\n// Map common win32 codes\n| extend scWin32Status_Friendly = case(\nscWin32Status_Hex =~ \"775\", \"The referenced account is currently locked out and cannot be logged on to.\",\nscWin32Status_Hex =~ \"52e\", \"Logon failure: Unknown user name or bad password.\",\nscWin32Status_Hex =~ \"532\", \"Logon failure: The specified account password has expired.\",\nscWin32Status_Hex =~ \"533\", \"Logon failure: Account currently disabled.\",\nscWin32Status_Hex =~ \"2ee2\", \"The request has timed out.\",\nscWin32Status_Hex =~ \"0\", \"The operation completed successfully.\",\nscWin32Status_Hex =~ \"1\", \"Incorrect function.\",\nscWin32Status_Hex =~ \"2\", \"The system cannot find the file specified.\",\nscWin32Status_Hex =~ \"3\", \"The system cannot find the path specified.\",\nscWin32Status_Hex =~ \"4\", \"The system cannot open the file.\",\nscWin32Status_Hex =~ \"5\", \"Access is denied.\",\nscWin32Status_Hex =~ \"8009030e\", \"SEC_E_NO_CREDENTIALS\",\nscWin32Status_Hex =~ \"8009030C\", \"SEC_E_LOGON_DENIED\",\n\"See - https://msdn.microsoft.com/library/cc231199.aspx\")\n// decode URI when available\n| extend decodedUriQuery = url_decode(csUriQuery)\n// Count of attempts by client IP on many ports\n| summarize makeset(sPort), makeset(decodedUriQuery), makeset(csUserName), makeset(sSiteName), makeset(sPort), makeset(csUserAgent), makeset(csMethod), makeset(csUriQuery), makeset(scStatusFull), makeset(scStatusFull_Friendly), makeset(scWin32Status_Hex), makeset(scWin32Status_Friendly), ConnectionsCount = count() by bin(TimeGenerated, timeBin), cIP, Computer, sIP\n| extend portCount = arraylength(set_sPort)\n| where portCount >= portThreshold\n| project TimeGenerated, cIP, set_sPort, set_csUserName, set_decodedUriQuery, Computer, set_sSiteName, sIP, set_csUserAgent, set_csMethod, set_scStatusFull, set_scStatusFull_Friendly, set_scWin32Status_Hex, set_scWin32Status_Friendly, ConnectionsCount, portCount\n| order by portCount\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1190"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}