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
triggerOperator: gt
triggerThreshold: 0
tactics:
- DefenseEvasion
queryFrequency: 1d
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}}
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
customDetails:
  EventName: EventName
  UserIdentityUserName: UserIdentityUserName
  AWSRegion: AWSRegion
  UserIdentityType: UserIdentityType
  UserAgent: UserAgent
  UserIdentityArn: UserIdentityArn
id: 4f19d4e3-ec5f-4abc-9e61-819eb131758c
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.
severity: Low
relevantTechniques:
- T1562.007
entityMappings:
- fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
  entityType: Account
- fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
  entityType: IP
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
- connectorId: AWSS3
  dataTypes:
  - AWSCloudTrail
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_IngressEgressSecurityGroupChange.yaml
status: Available
version: 1.0.5
queryPeriod: 1d

{
  "$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"
    }
  ]
}