AWSCloudTrail - Privilege escalation via CRUD DynamoDB policy

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Id	b9be2aa6-911d-4131-8658-d2a537ed49f4
Rulename	AWSCloudTrail - Privilege escalation via CRUD DynamoDB policy
Description	Detects creation of inline IAM policies that grant broad DynamoDB create, read, update, and delete permissions. Attackers may use this access expansion to manipulate data stores and escalate influence across cloud workloads.
Severity	Medium
Tactics	PrivilegeEscalation
Techniques	T1098.003
Required data connectors	AWS
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_PrivilegeEscalationviaCRUDDynamoDB.yaml
Version	1.0.2
Arm template	b9be2aa6-911d-4131-8658-d2a537ed49f4.json

KQL

AWSCloudTrail
| where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| extend PolicyName = tostring(parse_json(RequestParameters).policyName)
| extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
| mvexpand Statement
| extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
| extend Action = tostring(Action)
| where Effect =~ "Allow" and ((Action contains "dynamodb:Create" or Action contains "dynamodb:Put") and (Action contains "dynamodb:Describe" or Action contains "dynamodb:Get" or Action contains "dynamodb:Scan")  and Action contains "dynamodb:Update" and Action contains "dynamodb:Delete") and Resource == "*" and Condition == ""
| 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]), "")
| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName

YAML

entityMappings:
- fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
  entityType: Account
- fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
  entityType: IP
triggerOperator: gt
tactics:
- PrivilegeEscalation
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_PrivilegeEscalationviaCRUDDynamoDB.yaml
alertDetailsOverride:
  alertDescriptionFormat: Detected {{EventName}} Event, updating inline DynamoDB escalation policy {{PolicyName}} in account {{RecipientAccountId}}.
  alertDisplayNameFormat: AWS DynamoDB privilege escalation policy update by {{AccountName}}
version: 1.0.2
query: |
  AWSCloudTrail
  | where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend PolicyName = tostring(parse_json(RequestParameters).policyName)
  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
  | mvexpand Statement
  | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
  | extend Action = tostring(Action)
  | where Effect =~ "Allow" and ((Action contains "dynamodb:Create" or Action contains "dynamodb:Put") and (Action contains "dynamodb:Describe" or Action contains "dynamodb:Get" or Action contains "dynamodb:Scan")  and Action contains "dynamodb:Update" and Action contains "dynamodb:Delete") and Resource == "*" and Condition == ""
  | 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]), "")
  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName  
triggerThreshold: 0
relevantTechniques:
- T1098.003
queryPeriod: 1d
status: Available
severity: Medium
kind: Scheduled
customDetails:
  RecipientAccountId: RecipientAccountId
  EventName: EventName
  UserIdentityArn: UserIdentityArn
  PolicyName: PolicyName
name: AWSCloudTrail - Privilege escalation via CRUD DynamoDB policy
queryFrequency: 1d
id: b9be2aa6-911d-4131-8658-d2a537ed49f4
description: |
  Detects creation of inline IAM policies that grant broad DynamoDB create, read, update, and delete permissions.
  Attackers may use this access expansion to manipulate data stores and escalate influence across cloud workloads.  
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS

ARM