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analyzing-cloud-storage-access-patterns

Detect abnormal access in AWS S3, GCS, and Azure Blob Storage by analyzing CloudTrail Data Events, GCS audit logs, and Azure Storage Analytics for after-hours bulk downloads, new-IP access, and API-call spikes (e.g. GetObject) via statistical base...

Cybersecurity
MITRE ATT&CK
OWASP
By Anthropic Cybersecurity Skills (mukul975)
Target File: .cursor/rules/analyzing-cloud-storage-access-patterns.mdc
Type @rule-name in Cursor Chat
---
description: Detect abnormal access in AWS S3, GCS, and Azure Blob Storage by analyzing CloudTrail Data Events, GCS audit logs, and Azure Storage Analytics for after-hours bulk downloads, new-IP access, and API-call spikes (e.g. GetObject) via statistical base...
globs: *
alwaysApply: true
---

# analyzing-cloud-storage-access-patterns

# Analyzing Cloud Storage Access Patterns


## When to Use

- When investigating security incidents that require analyzing cloud storage access patterns
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques

## Prerequisites

- Familiarity with cloud security concepts and tools
- Access to a test or lab environment for safe execution
- Python 3.8+ with required dependencies installed
- Appropriate authorization for any testing activities

## Instructions

1. Install dependencies: `pip install boto3 requests`
2. Query CloudTrail for S3 Data Events using AWS CLI or boto3.
3. Build access baselines: hourly request volume, per-user object counts, source IP history.
4. Detect anomalies:
   - After-hours access (outside 8am-6pm local time)
   - Bulk downloads: >100 GetObject calls from single principal in 1 hour
   - New source IPs not seen in the prior 30 days
   - ListBucket enumeration spikes (reconnaissance indicator)
5. Generate prioritized findings report.

```bash
python scripts/agent.py --bucket my-sensitive-data --hours-back 24 --output s3_access_report.json
```

## Examples

### CloudTrail S3 Data Event
```json
{"eventName": "GetObject", "requestParameters": {"bucketName": "sensitive-data", "key": "financials/q4.xlsx"},
 "sourceIPAddress": "203.0.113.50", "userIdentity": {"arn": "arn:aws:iam::123456789012:user/analyst"}}
```

How to use this skill

  • • Cursor (Modern): Download as analyzing-cloud-storage-access-patterns.mdc and place it inside your project's .cursor/rules/ folder.
  • • Claude Code: Append the instructions to your project's root CLAUDE.md file.
  • • Cline / Roo Code: Save or append to .clinerules in your project root.
  • • Windsurf: Save or append to .windsurfrules.
  • • CLI Quick Add: npx awesome-ai-tools add analyzing-cloud-storage-access-patterns