Foreign account was granted permissions to S3 bucket via resource-based policy

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	N/A (single event)
Deduplication Period	1 Day
Required Data	AWS Audit Log
Detection Modules	Cloud
Detector Tags	Cloud Data Asset Exfiltration, Data Detection & Response
ATT&CK Tactic	Exfiltration (TA0010)
ATT&CK Technique	Transfer Data to Cloud Account (T1537)
Severity	Informational

Description

Foreign account was granted access to S3 bucket.

Attacker's Goals

• The attacker wants to maintain control over the resource.

Investigative actions

• Check if the {cloud_best_identity_match} intended to modify {aws_s3bucket_identifier} policy.
• Check the permissions that were granted to the {aws_grantee_project}.
• Restrict permissions for the {aws_grantee_project} if needed.

Variations

Foreign account was granted permissions to S3 bucket via resource-based policy with suspicious indicators

Synopsis

Field	Value
ATT&CK Tactic	Exfiltration (TA0010)
ATT&CK Technique	Transfer Data to Cloud Account (T1537)
Severity	Low

Description

Foreign account was granted access to S3 bucket.

Attacker's Goals

• The attacker wants to maintain control over the resource.

Investigative actions

• Check if the {cloud_best_identity_match} intended to modify {aws_s3bucket_identifier} policy.
• Check the permissions that were granted to the {aws_grantee_project}.
• Restrict permissions for the {aws_grantee_project} if needed.