S3 Object Exfiltration from Anonymous User

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Id	15d3bf4e-8708-41c8-a836-8b0aa5be730e
Rulename	S3 Object Exfiltration from Anonymous User
Description	Identify attempted exfiltration of S3 Bucket objects by an anonymous User
Severity	Medium
Tactics	Collection
Techniques	T1530
Required data connectors	AWS
Kind	Scheduled
Query frequency	5m
Query period	5m
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_S3ObjectExfiltrationByAnonymousUser.yaml
Version	1.0.0
Arm template	15d3bf4e-8708-41c8-a836-8b0aa5be730e.json

KQL

AWSCloudTrail
| where ((UserIdentityAccountId =~ @'ANONYMOUS_PRINCIPAL' or UserIdentityPrincipalid == "Anonymous") and EventName == 'GetObject')
| extend
   BucketName = parse_json(RequestParameters).bucketName,
   ObjectKey = parse_json(RequestParameters).key
| extend UserName = substring(UserIdentityPrincipalid, indexof_regex(UserIdentityPrincipalid, ":") + 1)
| extend Name = split(UserName,'@')[0],UpnSuffix = split(UserName,'@')[1]

YAML

requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_S3ObjectExfiltrationByAnonymousUser.yaml
triggerThreshold: 0
status: Available
relevantTechniques:
- T1530
queryPeriod: 5m
name: S3 Object Exfiltration from Anonymous User
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: Name
    identifier: Name
  - columnName: UpnSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
queryFrequency: 5m
triggerOperator: gt
kind: Scheduled
description: |
    'Identify attempted exfiltration of S3 Bucket objects by an anonymous User'
tactics:
- Collection
severity: Medium
version: 1.0.0
query: |
  AWSCloudTrail
  | where ((UserIdentityAccountId =~ @'ANONYMOUS_PRINCIPAL' or UserIdentityPrincipalid == "Anonymous") and EventName == 'GetObject')
  | extend
     BucketName = parse_json(RequestParameters).bucketName,
     ObjectKey = parse_json(RequestParameters).key
  | extend UserName = substring(UserIdentityPrincipalid, indexof_regex(UserIdentityPrincipalid, ":") + 1)
  | extend Name = split(UserName,'@')[0],UpnSuffix = split(UserName,'@')[1]  
id: 15d3bf4e-8708-41c8-a836-8b0aa5be730e

ARM