Exposed Google Cloud Storage Finder

An Exposed Google Cloud Storage (GCS) Finder is a specialized cybersecurity tool or methodology used to identify, inventory, and assess Google Cloud Storage buckets that have been inadvertently or intentionally configured with public access.

In a cloud environment, a "bucket" is a basic container that holds data. When a bucket is "exposed," it means the access control policies allow unauthenticated users (often referred to as allUsers in the Google Cloud Console) to list, read, or even write to the container. These tools simulate the reconnaissance phase of a cyberattack to help security teams identify "Shadow IT" and misconfigurations before they lead to a data breach.

How Exposed GCS Finders Work

Most finders operate using an "outside-in" approach, meaning they do not require any credentials or authorized access to the target organization's cloud environment. They generally follow a three-step process:

1. Bucket Name Discovery (Enumeration)

Because Google Cloud Storage bucket names must be globally unique across the entire platform, they often follow predictable naming conventions. Finders use permutation engines to guess names based on:

• Brand and Company Keywords: Scanners combine the company name with terms like "backups," "dev," "staging," "logs," or "finance."

• DNS and Certificate Logs: Monitoring public Certificate Transparency (CT) logs can reveal subdomains (e.g., files.example.com) that point to GCS endpoints.

• Passive Metadata Scraping: Analyzing website source code or mobile application binaries often uncovers hardcoded references to GCS buckets that store static assets.

2. Permissions Validation (Probing)

Once a potential bucket name is found, the finder sends an unauthenticated HTTP request to the Google Cloud Storage API. It checks for specific response codes to determine the access level:

• Listable (Public Listing): The finder can see the names and metadata of all files in the bucket. This is often flagged if storage.objects.list is granted to allUsers.

• Readable (Public Read): The finder can download specific files. This occurs when storage.objects.get is public.

• Writable (Public Write): The most dangerous state, where the finder can upload or delete files, potentially leading to website defacement or ransomware.

3. Risk Classification

Advanced finders do not just report the existence of a bucket; they analyze the "Digital Exhaust" within it. They may look for sensitive file extensions like .sql, .env, .pem, or .json to determine if the exposure contains PII (Personally Identifiable Information) or administrative credentials.

The Critical Risks of Exposed GCS Buckets

The detection of an exposed bucket is rarely a minor issue. It typically leads to one of the following high-impact security incidents:

• Data Exfiltration: Automated bots continuously crawl for open buckets to steal customer databases, financial records, and intellectual property.

• Supply Chain Attacks: If an attacker has write access to a bucket that hosts JavaScript libraries for a company's main website, they can inject malicious code to steal credit card data from site visitors.

• Credential Leaks: Buckets often contain developer backups that include hardcoded API keys or service account credentials, creating a lateral movement vector into the internal cloud network.

• Ransomware and Wipers: Attackers may delete the data in an open bucket and leave a ransom note, or simply wipe the data to cause business disruption.

Common Questions About GCS Bucket Finding

Is it legal to use a GCS bucket finder? Using a finder to scan for your own assets or as part of an authorized bug bounty program is a standard security practice. However, scanning and accessing organizations' data without their explicit permission can violate the Computer Fraud and Abuse Act (CFAA) and other privacy laws.

How do I prevent finders from seeing my buckets? The most effective defense is to enable Public Access Prevention (PAP) at the organization or project level. This acts as a "master switch" that overrides individual bucket settings, ensuring that no bucket can be made public, even if a user makes a configuration error.

Do GCS bucket finders require an agent? No. True finders are agentless. They operate entirely from the public internet, interacting with the Google Cloud API just as a web browser or a command-line tool would.

ThreatNG serves as an all-in-one platform for External Attack Surface Management (EASM) and Digital Risk Protection (DRP), providing a strictly "outside-in" view of an organization's digital footprint. By replicating the reconnaissance phase of a cyberattack, it identifies and evaluates exposed assets without requiring internal credentials or agents.

External Discovery

ThreatNG’s external discovery is the process of mapping an organization’s internet-accessible assets. Because it is unauthenticated, it uncovers the "unknown unknowns" that traditional internal tools often miss.

• Asset Identification: It identifies websites, servers, domains, subdomains, and cloud storage instances exposed to the public network.

• Shadow IT Detection: ThreatNG identifies unsanctioned deployments, such as a developer’s "sandbox" environment or a marketing microsite, that exist outside of central IT governance.

• Infrastructure Mapping: The platform analyzes DNS records, SSL certificates, and IP addresses to create a complete inventory of the organization's digital presence.

External Assessment

After discovery, ThreatNG performs focused assessments to validate the risk each asset poses. This phase moves beyond simple identification to examine the actual "susceptibility" of an asset to a breach.

• Detailed Example (Credential Leakage): ThreatNG assesses public code repositories for exposed Non-Human Identities (NHI), such as AWS Access Key IDs or SaaS tokens. If a developer accidentally commits a file containing these keys to GitHub, ThreatNG flags it as a critical exposure, giving an attacker the "keys to the cloud."

• Detailed Example (Subdomain Takeover): The platform evaluates subdomains for "dangling" DNS records—points where a subdomain points to a de-provisioned cloud service. An attacker could register that service and hijack the subdomain to host malicious content, damaging the organization’s brand.

Reporting

ThreatNG transforms raw data into actionable intelligence through customizable, prioritized reports.

• Risk Prioritization: Findings are ranked as High, Medium, or Low, enabling security teams to prioritize the most critical vulnerabilities.

• Security Ratings: The platform provides letter grades (A-F) that quantify the organization's external risk posture, making it easy to communicate security status to executives or board members.

• Compliance Overviews: Reports can map external findings directly to GRC (Governance, Risk, and Compliance) frameworks, highlighting gaps in regulatory requirements.

Continuous Monitoring

The attack surface is dynamic, with new subdomains and cloud instances appearing daily. ThreatNG maintains a 24/7 "uninterrupted watch" over the organization’s digital perimeter.

• Drift Detection: ThreatNG instantly alerts teams when a configuration changes—for example, if a previously closed administrative port (such as RDP or SSH) suddenly becomes accessible to the public internet.

• Real-Time Visibility: By continuously scanning the external landscape, ThreatNG ensures that transient misconfigurations do not become long-term risks.

Investigation Modules

Investigation modules provide deep forensic insights and context for the threats identified during discovery and assessment.

• Detailed Example (Cloud and SaaS Exposure): This module identifies sanctioned and unsanctioned cloud services (AWS, Azure, Google Cloud). For instance, it can uncover an open S3 bucket containing sensitive internal documents, providing immediate evidence of data leak risk.

• Detailed Example (Dark Web Presence): ThreatNG monitors dark web marketplaces and forums for mentions of the organization, its employees, or its cloud assets. This includes tracking ransomware events and identifying compromised credentials for sale.

• Detailed Example (Sensitive Code Exposure): This module investigates public code repositories for leaked secrets, configuration files, and mobile apps, uncovering clues to hidden APIs and potential entry points.

Intelligence Repositories

ThreatNG leverages extensive internal intelligence repositories, such as its DarCache, to enrich its findings with global threat data.

• Compromised Credentials Monitoring: This repository detects stolen credentials that could be used to bypass authentication for external services.

• Ransomware Tracking: ThreatNG tracks ransomware groups' tactics, techniques, and procedures (TTPs) to help organizations anticipate and prevent attacks.

Complementary Solutions

ThreatNG functions as a primary source of external intelligence, feeding its high-fidelity findings into other platforms to create a unified defense.

• Complementary Solution (Vulnerability Management - VM): While internal VM tools scan known internal IP ranges, ThreatNG provides the "Target List" of newly discovered external assets. This ensures the VM tool covers 100% of the actual attack surface.

• Complementary Solution (Cloud Security Posture Management - CSPM): ThreatNG identifies cloud exposure from the "outside-in" (e.g., an open bucket). This finding can be fed into a CSPM tool, which can then perform a deep, authenticated internal scan to understand the blast radius and perform auto-remediation.

• Complementary Solution (SIEM and SOAR): ThreatNG sends alerts to Security Information and Event Management (SIEM) systems, allowing SOC analysts to correlate external changes with internal network traffic. It also provides high-certainty evidence to Security Orchestration, Automation, and Response (SOAR) platforms to trigger automated responses, such as revoking a leaked API key or blocking a malicious IP address.

Common Questions About ThreatNG

Is ThreatNG's discovery unauthenticated? Yes. ThreatNG performs discovery from the perspective of an external attacker, meaning it requires no internal access, credentials, or agents to identify and assess assets.

How does ThreatNG handle Shadow IT? ThreatNG identifies Shadow IT by scanning for assets (subdomains, cloud buckets, APIs) that reference the organization's identity, regardless of whether they are officially sanctioned or managed by the IT department.

Can ThreatNG help with compliance? Yes. By identifying misconfigurations and exposed data that violate regulations like GDPR or HIPAA, ThreatNG provides the "outside-in" view required for a complete compliance assessment.