How to Document Proxy Usage for Compliance: Templates and Security Policies

If your company handles personal data of clients, processes payments, or is subject to security audits, documenting the use of proxy servers becomes a mandatory requirement. Lack of proper documentation can lead to fines of up to €20 million under GDPR or loss of PCI DSS certification.

In this guide, we will discuss how to properly document the use of proxies to comply with regulatory requirements, what policies need to be created, and how to maintain access logs. You will receive ready-made document templates and checklists for implementation.

Why Documenting Proxies is Critical for Compliance

Proxy servers often become a "blind spot" in corporate security documentation. Companies meticulously describe processes for handling databases but forget to document how their employees or systems access external resources through proxies.

The issue becomes critical in several situations:

• Information Security Audit: ISO 27001 or SOC 2 auditors require confirmation that all data access channels are documented and controlled. Proxies are one such access channel.
• Incident Investigation: In the event of a data breach or suspected fraud, you need to prove who, when, and why used the proxy to access certain resources.
• GDPR Compliance Check: If you process data of EU citizens through proxies in other countries, you need to document the legality of cross-border data transfers.
• PCI DSS Certification: For companies accepting card payments, all access points to card data must be documented, including proxy servers.

A real example: in 2022, a European fintech company received a warning from the regulator for lacking documentation on how their risk-monitoring system uses proxies to verify transactions. They avoided a fine only after urgently creating a complete documentation package and retrospective logs for 12 months.

What Regulatory Requirements Affect Proxies

Various regulatory standards impose specific requirements for documenting the use of proxy servers. Here are the main ones that businesses encounter:

GDPR (General Data Protection Regulation)

If you use proxies to process personal data of EU citizens, you need to document:

• The purposes of using proxies (Article 5.1.b — purpose limitation)
• Geographical location of proxy servers (Article 44 — cross-border data transfer)
• Security measures to protect data during transmission via proxies (Article 32)
• Contracts with the proxy provider as a data processor (Article 28)
• Access logs to ensure accountability (Article 5.2)

A practical example: if your marketing department uses residential proxies to analyze competitors in different EU countries, and collects data on prices or assortments (which may indirectly contain personal data), you need a GDPR-compliant proxy usage policy.

PCI DSS (Payment Card Industry Data Security Standard)

For companies processing payments, PCI DSS version 4.0 requirements include:

• Requirement 1.2.1: Documenting all allowed connections between the card data environment and external networks (proxies are such connections)
• Requirement 10.2: Keeping logs of all actions by users with administrative rights, including proxy management
• Requirement 12.3: Policy on the use of technologies, including proxy servers

ISO 27001 (Information Security Management System)

The standard requires documentation in the context of control A.13.1.1 (management of network security elements):

• Inventory of all proxy servers and their configurations
• Access management procedures for proxies
• Monitoring usage and detecting anomalies
• Regular review of policies (at least annually)

152-FZ "On Personal Data" (Russia)

Russian legislation requires documentation of:

• Threat model for personal data security (proxy as a means of protection or potential threat)
• Technical specifications for creating or modernizing an information system (if the proxy is part of it)
• Acts of classification and categorization of information systems

Proxy Usage Policy Template

The proxy usage policy is a foundational document that defines the rules, responsibilities, and procedures. Here is a structure for the policy, adapted to compliance requirements:

1. General Provisions

Purpose of the Policy: To define the rules for using proxy servers to ensure security, privacy, and compliance with regulatory requirements when accessing external resources and processing data.

Scope: The policy applies to all employees, contractors, and automated systems of the company using proxy servers to access internet resources or process data.

2. Allowed Purposes for Using Proxies

Proxy servers may only be used for the following business purposes:

• Competitor Monitoring: Collecting publicly available information about prices, assortments, and marketing activities of competitors for market analysis (departments: marketing, product).
• Web Service Testing: Checking the availability and correctness of the operation of own web resources from different geographical regions (departments: development, QA).
• Advertising Campaign Verification: Checking the display of advertisements in different regions and on different devices (department: marketing).
• DDoS Protection: Masking the IP addresses of corporate systems when accessing external APIs (department: IT).
• Anonymity Assurance: Protecting the personal data of employees when conducting research or working with sensitive information (department: security, compliance).

3. Types of Proxies and Their Applications

4. Procedure for Accessing Proxies

Any employee needing access to proxy servers must follow this procedure:

1. Application Submission: Filling out an access request form specifying the business justification, type of proxy, and duration of use.
2. Approval from Supervisor: Approval from the immediate supervisor of the department.
3. Compliance Check: Evaluation of the request by the information security or compliance department for policy adherence.
4. Credential Issuance: The IT department provides access with unique credentials for each user.
5. Training: The employee undergoes a brief training on the safe use of proxies (can be in the form of a video or document).

Application Review Period: No more than 3 business days from the date of submission.

5. Responsibilities and Roles

• Chief Information Security Officer (CISO): Policy approval, compliance monitoring, audit coordination.
• IT Department: Technical implementation, access issuance, monitoring of proxy infrastructure.
• Compliance Officer: Ensuring the use of proxies complies with regulatory requirements, maintaining documentation.
• Department Heads: Approving requests from their employees, monitoring targeted use.
• End Users: Adhering to the policy, immediately reporting any incidents or suspicious activity.

Access and Monitoring Logs: What to Record

Maintaining logs of proxy usage is not just a technical necessity but a mandatory requirement of most compliance standards. Logs allow tracking who, when, and for what purposes used the proxy, as well as identifying anomalies or unauthorized access.

Mandatory Fields in Access Logs

Each log entry must contain the following data:

Automating Log Collection

Most proxy providers offer APIs for obtaining usage statistics. Integrate this data into your SIEM (Security Information and Event Management) system or centralized log storage.

Recommended tools for log collection and analysis:

• ELK Stack (Elasticsearch, Logstash, Kibana): A free solution for small and medium businesses, allows visualizing proxy usage in real-time.
• Splunk: A commercial platform with powerful event correlation and anomaly detection capabilities.
• Graylog: An open-source alternative to Splunk with a simple interface.
• Azure Monitor / AWS CloudWatch: Cloud solutions for companies using the respective platforms.

Setting Up Alerts

Automated alerts help identify policy violations or suspicious activity:

• Unusual Data Volume: If an employee transmitted more than 1 GB through the proxy in a session (may indicate downloading databases).
• Access During Non-Working Hours: Using the proxy during nighttime or weekends without prior approval.
• Geolocation Change: One user uses proxies from 5+ different countries in a short period.
• Access to Prohibited Resources: Attempting to connect to domains on the company's blacklist.
• Multiple Failed Attempts: More than 10 failed authentication attempts in an hour (possible credential compromise).

Documenting Personal Data Protection via Proxies

If your systems process personal data through proxies (for example, for user verification, fraud transaction checks, or analytics collection), you need to document the protective measures for this data.

Data Processing Impact Assessment (DPIA) for Proxies

GDPR requires conducting a Data Protection Impact Assessment (DPIA) for processing operations that may pose a high risk to the rights and freedoms of individuals. The use of proxies may fall under this requirement if:

• You process sensitive personal data (health, finance, biometrics)
• You use proxies in countries with inadequate data protection (non-EU)
• You process data on a large scale (more than 10,000 data subjects)

The structure of a DPIA for using proxies:

1. Description of Processing: What data is transmitted through the proxy, for what purposes, and which categories of data subjects are affected.
2. Necessity and Proportionality: Justification of why using proxies is necessary and that there are no less risky alternatives.
3. Risks to Data Subjects: What could go wrong (data breach, unauthorized access, loss of control over data).
4. Risk Mitigation Measures: Encryption, access restrictions, contracts with the proxy provider, regular audits.
5. Consultation with DPO: If you have a Data Protection Officer, their opinion should be documented.

Contract with Proxy Provider as Data Processor

If the proxy provider has the technical capability to access personal data passing through its servers, it legally becomes a "data processor" under GDPR terminology.

The contract with the provider should specify:

• Subject and Duration of Processing: What data is processed, for how long.
• Processor Obligations: Ensuring security, confidentiality, assisting in the implementation of data subjects' rights.
• Sub-processors: Whether the provider can engage third parties, whether your consent is required.
• Cross-Border Transfer: In which countries the proxy servers are located, what protection mechanisms are applied (Standard Contractual Clauses, Adequacy Decision).
• Incident Notification: The provider's obligation to immediately inform about any data security breaches.
• Audits and Inspections: Your right to verify the provider's compliance with the contract terms.

Data Encryption During Transmission via Proxies

Document what encryption methods are applied:

• HTTPS Proxies: All traffic between your system and the proxy server is encrypted using TLS 1.2 or higher.
• SOCKS5 with SSH Tunnel: An additional level of encryption for particularly sensitive data.
• End-to-End Encryption: Data is encrypted on the sender's side and decrypted only on the recipient's side; the proxy sees only encrypted traffic.

In the documentation, specify protocol versions and encryption algorithms (e.g., "TLS 1.3 with AES-256-GCM").

Preparing Documentation for Audit

When the time for an external or internal audit comes, you need to quickly provide a complete package of documents confirming compliance with the use of proxies. Here’s what should be prepared in advance:

Audit Document Package

1. Proxy Usage Policy (current version with the approving authority's signature)
   • History of policy changes
   • Documents confirming employee familiarization (signed or electronic confirmations)
2. Inventory of Proxy Servers
   • List of all proxies used (IP addresses, geographical locations, types)
   • Information about providers (company names, contact details, contract details)
   • Date of commencement of use for each proxy
3. Access Logs
   • Logs for the last 12 months (or the period required by your standard)
   • Reports on identified anomalies and measures taken
   • Usage statistics by departments
4. Contracts with Providers
   • Main contract for proxy services
   • Data Processing Agreement (DPA) for GDPR compliance
   • Standard Contractual Clauses (SCC) if proxies are located outside the EU
   • SLA (Service Level Agreement) with guarantees of availability and security
5. DPIA (Data Protection Impact Assessment) — if applicable
6. Access Management Procedures
   • Access request form for proxies
   • Examples of approved and denied requests
   • Procedure for revoking access upon employee termination
7. Incidents and Their Investigation
   • Incident register related to proxies (if any)
   • Investigation reports
   • Corrective actions
8. Training and Awareness
   • Training materials on safe proxy usage
   • Records of employee training completion

Typical Auditor Questions

Be prepared to answer the following questions (with evidence):

• "How do you control that proxies are used only for allowed purposes?" — Show logs and monitoring procedures.
• "How do you ensure that personal data does not reach the proxy provider?" — Show DPA, encryption policy, no-log confirmation.
• "How often do you review the list of employees with access to proxies?" — Show the quarterly review procedure.
• "What will happen if the proxy provider ceases operations or is compromised?" — Show the business continuity plan (BCP) and a list of alternative providers.
• "How do you ensure compliance during cross-border data transfers?" — Show SCC and analysis of the countries where proxies are located.

Automating Audit Preparation

Create an "audit folder" (physical or electronic) with current versions of all documents. Assign someone responsible for its updates (usually the compliance officer or CISO).

Use GRC platforms (Governance, Risk, Compliance) for automation:

• OneTrust: Policy management, automatic reminders for document reviews.
• ServiceNow GRC: Integration with IT processes, automatic collection of compliance evidence.
• Vanta / Drata: Compliance automation for SOC 2, ISO 27001 with continuous monitoring.

Document and Log Retention Periods

Various standards and legislations establish minimum retention periods for documentation and logs. Non-compliance with these periods can lead to fines or the inability to prove compliance in case of an investigation.

Safe Deletion Procedure

After the retention period expires, documents and logs must be safely deleted to minimize the risk of leaking outdated data:

• Electronic Documents: Use secure deletion methods (not just "Delete," but overwrite data at least 3 times).
• Paper Documents: Destruction via shredder with a security level of P-4 or higher (according to DIN 66399).
• Backups: Do not forget to delete data from all backups, not just from the main storage.
• Deletion Documentation: Keep logs of the deletion process.