AWSCloudTrail - Changes to AWS Security Group ingress and egress settings

let EventNameList = dynamic([ "AuthorizeSecurityGroupEgress", "AuthorizeSecurityGroupIngress", "RevokeSecurityGroupEgress", "RevokeSecurityGroupIngress"]);
AWSCloudTrail
| where EventName in~ (EventNameList)
| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
| summarize EventCount=count(), StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated)
by EventSource, EventName, UserIdentityType, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
AdditionalEventData, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements

name: AWSCloudTrail - Changes to AWS Security Group ingress and egress settings
tactics:
- DefenseEvasion
alertDetailsOverride:
  alertDisplayNameFormat: AWS Security Group ingress/egress change by {{AccountName}} from {{SourceIpAddress}}
  alertDescriptionFormat: AWS Security Group ingress/egress change activity {{EventName}} was detected for {{AccountName}} from {{SourceIpAddress}}.
queryFrequency: 1d
triggerThreshold: 0
customDetails:
  EventName: EventName
  UserIdentityType: UserIdentityType
  UserAgent: UserAgent
  UserIdentityArn: UserIdentityArn
  AWSRegion: AWSRegion
  UserIdentityUserName: UserIdentityUserName
relevantTechniques:
- T1562.007
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_IngressEgressSecurityGroupChange.yaml
kind: Scheduled
description: |
  A Security Group acts as a virtual firewall for an AWS instance to control inbound and outbound traffic. This rule detects AWS CloudTrail events for changes to Security Group ingress and egress settings.
  Investigate to validate the legitimacy of the activity and identify potential malicious activity.
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
- connectorId: AWSS3
  dataTypes:
  - AWSCloudTrail
status: Available
severity: Low
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
  entityType: IP
queryPeriod: 1d
query: |
  let EventNameList = dynamic([ "AuthorizeSecurityGroupEgress", "AuthorizeSecurityGroupIngress", "RevokeSecurityGroupEgress", "RevokeSecurityGroupIngress"]);
  AWSCloudTrail
  | where EventName in~ (EventNameList)
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | summarize EventCount=count(), StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated)
  by EventSource, EventName, UserIdentityType, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
  AdditionalEventData, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements
triggerOperator: gt
version: 1.0.5
id: 4f19d4e3-ec5f-4abc-9e61-819eb131758c

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/4f19d4e3-ec5f-4abc-9e61-819eb131758c')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/4f19d4e3-ec5f-4abc-9e61-819eb131758c')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "AWS Security Group ingress/egress change activity {{EventName}} was detected for {{AccountName}} from {{SourceIpAddress}}.",
          "alertDisplayNameFormat": "AWS Security Group ingress/egress change by {{AccountName}} from {{SourceIpAddress}}"
        },
        "alertRuleTemplateName": "4f19d4e3-ec5f-4abc-9e61-819eb131758c",
        "customDetails": {
          "AWSRegion": "AWSRegion",
          "EventName": "EventName",
          "UserAgent": "UserAgent",
          "UserIdentityArn": "UserIdentityArn",
          "UserIdentityType": "UserIdentityType",
          "UserIdentityUserName": "UserIdentityUserName"
        },
        "description": "A Security Group acts as a virtual firewall for an AWS instance to control inbound and outbound traffic. This rule detects AWS CloudTrail events for changes to Security Group ingress and egress settings.\nInvestigate to validate the legitimacy of the activity and identify potential malicious activity.\n",
        "displayName": "AWSCloudTrail - Changes to AWS Security Group ingress and egress settings",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              },
              {
                "columnName": "RecipientAccountId",
                "identifier": "CloudAppAccountId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_IngressEgressSecurityGroupChange.yaml",
        "query": "let EventNameList = dynamic([ \"AuthorizeSecurityGroupEgress\", \"AuthorizeSecurityGroupIngress\", \"RevokeSecurityGroupEgress\", \"RevokeSecurityGroupIngress\"]);\nAWSCloudTrail\n| where EventName in~ (EventNameList)\n| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)\n| extend UserName = tostring(split(UserIdentityArn, '/')[-1])\n| extend AccountName = case( UserIdentityPrincipalid == \"Anonymous\", \"Anonymous\", isempty(UserIdentityUserName), UserName, UserIdentityUserName)\n| extend AccountName = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 0)[0]), AccountName),\n  AccountUPNSuffix = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 1)[0]), \"\")\n| summarize EventCount=count(), StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated)\nby EventSource, EventName, UserIdentityType, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,\nAdditionalEventData, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [
          "T1562.007"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1562"
        ],
        "templateVersion": "1.0.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}