Changes to AWS Elastic Load Balancer security groups

Back


Id	c7bfadd4-34a6-4fa5-82f8-3691a32261e8
Rulename	Changes to AWS Elastic Load Balancer security groups
Description	Elastic Load Balancer distributes incoming traffic across multiple instances in multiple availability Zones. This increases the fault tolerance of your applications. Unwanted changes to Elastic Load Balancer specific security groups could open your environment to attack and hence needs monitoring. More information: https://medium.com/@GorillaStack/the-most-important-aws-cloudtrail-security-events-to-track-a5b9873f8255 and https://aws.amazon.com/elasticloadbalancing/.
Severity	Low
Tactics	Persistence
Techniques	T1098
Required data connectors	AWS AWSS3
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_LoadBalancerSecGroupChange.yaml
Version	1.0.3
Arm template	c7bfadd4-34a6-4fa5-82f8-3691a32261e8.json

KQL

let EventNameList = dynamic(["ApplySecurityGroupsToLoadBalancer", "SetSecurityGroups"]);
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,  SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
AdditionalEventData, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements
| extend timestamp = StartTimeUtc

YAML

relevantTechniques:
- T1098
name: Changes to AWS Elastic Load Balancer security groups
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
- dataTypes:
  - AWSCloudTrail
  connectorId: AWSS3
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
  entityType: IP
triggerThreshold: 0
id: c7bfadd4-34a6-4fa5-82f8-3691a32261e8
tactics:
- Persistence
version: 1.0.3
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_LoadBalancerSecGroupChange.yaml
queryPeriod: 1d
kind: Scheduled
queryFrequency: 1d
severity: Low
status: Available
description: |
  'Elastic Load Balancer distributes incoming traffic across multiple instances in multiple availability Zones. This increases the fault tolerance of your applications.
   Unwanted changes to Elastic Load Balancer specific security groups could open your environment to attack and  hence needs monitoring.
   More information: https://medium.com/@GorillaStack/the-most-important-aws-cloudtrail-security-events-to-track-a5b9873f8255 
   and https://aws.amazon.com/elasticloadbalancing/. '  
query: |
  let EventNameList = dynamic(["ApplySecurityGroupsToLoadBalancer", "SetSecurityGroups"]);
  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,  SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
  AdditionalEventData, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements
  | extend timestamp = StartTimeUtc  
triggerOperator: gt

ARM

{
  "$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/c7bfadd4-34a6-4fa5-82f8-3691a32261e8')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/c7bfadd4-34a6-4fa5-82f8-3691a32261e8')]",
      "properties": {
        "alertRuleTemplateName": "c7bfadd4-34a6-4fa5-82f8-3691a32261e8",
        "customDetails": null,
        "description": "'Elastic Load Balancer distributes incoming traffic across multiple instances in multiple availability Zones. This increases the fault tolerance of your applications.\n Unwanted changes to Elastic Load Balancer specific security groups could open your environment to attack and  hence needs monitoring.\n More information: https://medium.com/@GorillaStack/the-most-important-aws-cloudtrail-security-events-to-track-a5b9873f8255 \n and https://aws.amazon.com/elasticloadbalancing/. '\n",
        "displayName": "Changes to AWS Elastic Load Balancer security groups",
        "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 Web Services/Analytic Rules/AWS_LoadBalancerSecGroupChange.yaml",
        "query": "let EventNameList = dynamic([\"ApplySecurityGroupsToLoadBalancer\", \"SetSecurityGroups\"]);\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,  SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,\nAdditionalEventData, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements\n| extend timestamp = StartTimeUtc\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}