Browse Rules

AWS Discovery API Calls via CLI from a Single Resource

Detects when a single AWS resource is running multiple read-only, discovery API calls in a 10-second window. This behavior could indicate an actor attempting to discover the AWS infrastructure using compromised credentials or a compromised instance. Adversaries may use this information to identify potential targets for further exploitation or to gain a better understanding of the target's infrastructure.

AWS S3 Object Encryption Using External KMS Key

Identifies use of the S3 CopyObject API where the destination object is encrypted using an AWS KMS key from an external AWS account. This behavior may indicate ransomware-style impact activity where an adversary with access to a misconfigured S3 bucket encrypts objects using a KMS key they control, preventing the bucket owner from decrypting their own data. This technique is a critical early signal of destructive intent or cross-account misuse.

AWS S3 Unauthenticated Bucket Access by Rare Source

Identifies AWS CloudTrail events where an unauthenticated source is attempting to access an S3 bucket. This activity may indicate a misconfigured S3 bucket policy that allows public access to the bucket, potentially exposing sensitive data to unauthorized users. Adversaries can specify --no-sign-request in the AWS CLI to retrieve objects from an S3 bucket without authentication. This is a New Terms rule, which means it will trigger for each unique combination of the source.address and targeted b

AWS API Activity from Uncommon S3 Client by Rare User

Identifies AWS API activity originating from uncommon desktop client applications based on the user agent string. This rule detects S3 Browser and Cyberduck, which are graphical S3 management tools that provide bulk upload/download capabilities. While legitimate, these tools are rarely used in enterprise environments and have been observed in use by threat actors for data exfiltration. Any activity from these clients should be validated against authorized data transfer workflows.

AWS S3 Credential File Retrieved from Bucket

Detects successful S3 GetObject calls targeting high-value credential and secret files commonly stored in S3 buckets: AWS credentials files (".aws/credentials", ".aws/config"), SSH private keys ("id_rsa", "id_ed25519", "id_ecdsa", "id_dsa"), environment files (".env"), PEM and PuTTY key files, and other private key patterns. These file types are high-yield targets for credential harvesting from S3. The rule excludes AWSService identity type to suppress S3 replication, Glacier restore, and other

AWS S3 Bucket Enumeration or Brute Force

Identifies a high number of failed S3 operations against a single bucket from a single source address within a short timeframe. This activity can indicate attempts to collect bucket objects or cause an increase in billing to an account via internal "AccessDenied" errors.

AWS S3 Static Site JavaScript File Uploaded

This rule detects when a JavaScript file is uploaded in an S3 static site directory (`static/js/`) by an IAM user or assumed role. This can indicate suspicious modification of web content hosted on S3, such as injecting malicious scripts into a static website frontend.

Potential AWS S3 Bucket Ransomware Note Uploaded

Identifies potential ransomware note being uploaded to an AWS S3 bucket. This rule detects the PutObject S3 API call with an object name commonly associated with ransomware notes. The keywords detected here rarely overlap with common file names and have been attributed to ransomware notes with high-confidence. Adversaries with access to a misconfigured S3 bucket may retrieve, delete, and replace objects with ransom notes to extort victims.

AWS S3 Rapid Bucket Posture API Calls from a Single Principal

Identifies when the same AWS principal, from the same source IP, successfully invokes read-only S3 control-plane APIs that reveal bucket posture across many buckets in a short period. This pattern can indicate automated reconnaissance or security scanning, similar to CSPM tools and post-compromise enumeration. The rule excludes AWS service principals, requires programmatic-style sessions (not Management Console credentials), and requires populated resource and identity fields so nulls do not ske

AWS S3 Bucket Policy Added to Allow Public Access

Detects when an Amazon S3 bucket policy is modified to grant public access using a wildcard (Principal:"*") statement. This rule analyzes PutBucketPolicy events that include both Effect=Allow and Principal:"*" in the request parameters, indicating that permissions were extended to all identities, potentially making the bucket or its contents publicly accessible. Publicly exposing an S3 bucket is one of the most common causes of sensitive data leaks in AWS environments. Adversaries or misconfigur

Excessive AWS S3 Object Encryption with SSE-C

Identifies a high-volume of AWS S3 objects stored in a bucket using using Server-Side Encryption with Customer-Provided Keys (SSE-C). Adversaries with compromised AWS credentials can encrypt objects in an S3 bucket using their own encryption keys, rendering the objects unreadable or recoverable without the key. This can be used as a form of ransomware to extort the bucket owner for the decryption key. This is a Threshold rule that triggers when this behavior is observed multiple times for a spec

Unusual AWS S3 Object Encryption with SSE-C

Identifies when AWS S3 objects stored in a bucket are encrypted using Server-Side Encryption with Customer-Provided Keys (SSE-C). Adversaries with compromised AWS credentials can encrypt objects in an S3 bucket using their own encryption keys, rendering the objects unreadable or recoverable without the key. This can be used as a form of ransomware to extort the bucket owner for the decryption key. This is a New Terms rule that flags when this behavior is observed for the first time user and targ

AWS DynamoDB Table Exported to S3

Identifies when an AWS DynamoDB table is exported to S3. Adversaries may use the ExportTableToPointInTime operation to collect sensitive information or exfiltrate data from DynamoDB tables. This rule detects unusual user activity by monitoring for the ExportTableToPointInTime action in CloudTrail logs. This is a New Terms rule that only flags when this behavior is observed by a user or role for the first time.

AWS S3 Bucket Replicated to Another Account

Identifies the creation or modification of an S3 bucket replication configuration that sends data to a bucket in a different AWS account. Cross-account replication can be used legitimately for backup, disaster recovery, and multi-account architectures, but adversaries with write access to an S3 bucket may abuse replication rules to silently exfiltrate large volumes of data to attacker-controlled accounts. This rule detects "PutBucketReplication" events where the configured destination account di

AWS S3 Object Exfiltration WITH Object Deletion

Detects a ransomware attack pattern where an attacker with compromised AWS credentials exfiltrates data from an S3 bucket to an external AWS account, followed by bulk deletion of objects from the source bucket within a short timeframe. This technique was notably used by the threat actor Bling Libra to extort victims by threatening data destruction or leaks.

AWS S3 Bucket Server Access Logging Disabled

Identifies when server access logging is disabled for an Amazon S3 bucket. Server access logs provide a detailed record of requests made to an S3 bucket. When server access logging is disabled for a bucket, it could indicate an adversary's attempt to impair defenses by disabling logs that contain evidence of malicious activity.

AWS RDS DB Instance Restored

Identifies the restoration of an AWS RDS database instance from a snapshot or S3 backup. Adversaries with access to valid credentials may restore copies of existing databases to bypass logging and monitoring controls or to exfiltrate sensitive data from a duplicated environment. This rule detects successful restoration operations using "RestoreDBInstanceFromDBSnapshot" or "RestoreDBInstanceFromS3", which may indicate unauthorized data access or post-compromise defense evasion.

AWS S3 Bucket Configuration Deletion

Identifies the deletion of critical Amazon S3 bucket configurations such as bucket policies, lifecycle configurations or encryption settings. These actions are typically administrative but may also represent adversarial attempts to remove security controls, disable data retention mechanisms, or conceal evidence of malicious activity. Adversaries who gain access to AWS credentials may delete logging, lifecycle, or policy configurations to disrupt forensic visibility and inhibit recovery. For exam

AWS S3 Bucket MFA Delete Disabled

Detects when MFA Delete is disabled on an Amazon S3 bucket. MFA Delete is an additional layer of security for versioned S3 buckets that requires multi-factor authentication to permanently delete object versions or disable versioning. When MFA Delete is disabled, an adversary with S3 write access and a compromised long-term access key can permanently delete object versions, a critical step in ransomware attacks that target S3 versioning as a backup mechanism. MFA Delete is configured via PutBucke

Unusual High Denied Topic Blocks Detected

Detects repeated compliance violation 'BLOCKED' actions coupled with specific policy name such as 'topic_policy', indicating persistent misuse or attempts to probe the model's denied topics.

Unusual High Word Policy Blocks Detected

Detects repeated compliance violation 'BLOCKED' actions coupled with specific policy name such as 'word_policy', indicating persistent misuse or attempts to probe the model's denied topics.

AWS S3 Bucket Expiration Lifecycle Configuration Added

Identifies the addition of an expiration lifecycle configuration to an Amazon S3 bucket. S3 lifecycle rules can automatically delete or transition objects after a defined period. Adversaries can abuse them by configuring auto-deletion of logs, forensic evidence, or sensitive objects to cover their tracks. This rule detects the use of the PutBucketLifecycle or PutBucketLifecycleConfiguration APIs with Expiration parameters, which may indicate an attempt to automate the removal of data to hinder i

Suspicious AWS S3 Connection via Script Interpreter

Detects when a script interpreter (osascript, Node.js, Python) with minimal arguments makes an outbound connection to AWS S3 or CloudFront domains. Threat actors have used S3 buckets for both command and control and data exfiltration. Script interpreters connecting to cloud storage should be investigated for potential malicious activity.

AWS Backup Recovery Point Deleted

Identifies deletion of an AWS Backup recovery point via DeleteRecoveryPoint. A recovery point is a stored backup of a protected resource (EBS, RDS, DynamoDB, EFS, S3, and others). Deleting recovery points removes the ability to restore the associated data and is a core anti-recovery technique used in ransomware and data-destruction attacks to ensure victims cannot recover without paying or rebuilding. Routine lifecycle expirations are performed by the AWS Backup service itself; deletion by a non

AWS Bedrock Detected Multiple Attempts to use Denied Models by a Single User

Identifies multiple successive failed attempts to use denied model resources within AWS Bedrock. This could indicated attempts to bypass limitations of other approved models, or to force an impact on the environment by incurring exhorbitant costs.