How to Protect Against Man-in-the-Middle Attacks When Using Proxies: A Guide for Arbitrage

When working with dozens of Facebook Ads accounts or managing client profiles on Instagram through proxies, data security becomes critically important. Man-in-the-middle (MITM) attacks are a real threat where an attacker intercepts traffic between you and the target site, gaining access to passwords, tokens, and payment information. In this guide, we will explore how to protect against such attacks when using proxy servers.

What is a MITM Attack and Why Proxies are a Vulnerability Point

Man-in-the-middle (MITM) is a type of cyber attack where an attacker secretly intercepts and potentially alters communication between two parties. In the context of working through proxies, this means that a malicious provider or hacker who gains access to the proxy server can see all your traffic.

Why do proxies become a vulnerability point? When you connect to the internet through a proxy server, all your traffic passes through this intermediary node. If the connection is not properly secured, the proxy owner can technically intercept:

• Logins and passwords for Facebook Ads, TikTok Ads, Google Ads accounts
• API access tokens for social networks
• Credit card information when topping up advertising budgets
• Authentication cookies that allow access to accounts without a password
• Correspondence in messengers and confidential business information

This situation is especially dangerous for arbitrageurs working with large advertising budgets and SMM agencies managing dozens of client accounts. One compromised proxy can lead to loss of access to all accounts that were working through it.

Real Risks for Arbitrageurs and SMM Specialists

Let's consider specific scenarios of how a MITM attack through a compromised proxy can impact your business:

Scenario 1: Arbitrageur Loses Advertising Accounts

You are using Dolphin Anty to farm Facebook Ads accounts, connecting cheap proxies from an unknown provider. Authorization in Facebook Business Manager, where cards with a budget of $10,000 are linked, goes through the proxy. The attacker intercepts session cookies and gains access to your Business Manager. The result:

• Drain of advertising budget on unauthorized campaigns
• Change of payment information and withdrawal of funds
• Blocking of all accounts due to suspicious activity
• Loss of access to warmed-up accounts worth $100-500 each

Scenario 2: SMM Agency Loses Client Accounts

Your agency manages 30 client Instagram accounts through a proxy. One of the proxy servers is compromised, and the attacker gains access to authorization tokens. Consequences:

• Posting spam or malicious content on behalf of clients
• Changing passwords and losing access to accounts
• Reputational damage for clients and your agency
• Contract termination and lawsuits

Scenario 3: Interception of Payment Data

When topping up an advertising budget through an unsecured proxy connection, your card data may be intercepted. Even if the site uses HTTPS, some types of MITM attacks allow bypassing encryption at the proxy server level.

How Traffic Interception Works via Proxies

To effectively defend against attacks, you need to understand the mechanics of the attack. Here are the main methods that attackers use to intercept data through proxy servers:

Method 1: SSL Stripping (Downgrading Encryption)

This is the most common technique of MITM attacks through proxies. The attacker intercepts your request to an HTTPS site and substitutes it with the HTTP version. You think you are working over a secure connection, but in reality, the traffic is transmitted in plain text.

How this works in the context of working through a proxy:

1. You enter the address facebook.com in Dolphin Anty
2. The request goes through the attacker's proxy server
3. The proxy intercepts the request and substitutes https:// with http://
4. Facebook serves an unprotected version of the page (if available)
5. You enter your password, which is sent in plain text through the proxy
6. The attacker saves your data and forwards the request

Method 2: SSL Certificate Substitution

A more complex technique where the proxy server acts as an intermediary between you and the target site, substituting the SSL certificate. The proxy establishes its own certificate for the connection with you, while establishing a legitimate HTTPS connection with the site.

Protection: modern browsers (including anti-detect browser engines) show a warning about an untrusted certificate. If you see such a warning while working through a proxy — it's a red flag, immediately stop using this proxy.

Method 3: Traffic Logging by the Provider

Some unscrupulous proxy providers intentionally log all user traffic for subsequent analysis and data sale. This is not a classic MITM attack, but the result is the same — your data ends up in the wrong hands.

Particularly dangerous in this regard are:

• Free proxies from public lists
• Proxies from providers without a clear privacy policy
• Too cheap proxies (prices 3-5 times lower than the market)
• Proxies from providers in countries with low data protection

How to Check the Reliability of a Proxy Provider

Choosing a reliable proxy provider is the first and most important line of defense against MITM attacks. Here are specific criteria to assess the provider's security:

Criterion 1: Transparent Privacy Policy

A reliable provider should clearly state in their privacy policy:

• No-logs policy — no logging of user traffic
• What technical data is collected (usually only traffic usage metrics)
• How long connection data is stored
• Under what circumstances data may be shared with third parties

If the provider's website lacks a privacy policy or it is written extremely vaguely — this is a serious reason to refuse their services.

Criterion 2: Reputation and Reviews

Check the provider through the following sources:

• Reviews in specialized arbitrage communities (Telegram channels, forums)
• Mentions in the context of working with Facebook Ads, TikTok Ads — if the provider is popular among arbitrageurs, it's a good sign
• How long the provider has been in the market — new companies are riskier
• Availability of case studies and public clients

Criterion 3: Technical Security Guarantees

Ask the provider direct questions in support:

• Is HTTPS traffic supported without decryption on the proxy side?
• Is there logging of HTTP requests and cookies?
• What protocols are supported (HTTP, HTTPS, SOCKS5)?
• Is the connection between your device and the proxy server encrypted?

A quality provider, for example, offering residential proxies, should clearly and thoroughly answer these questions. Evasive answers or ignoring questions are a bad sign.

Criterion 4: Adequate Pricing Policy

A price that is too low is always suspicious. Maintaining the infrastructure of quality proxies costs money. If a provider offers prices 3-5 times lower than the market, they are likely profiting in another way — most likely from your data.

HTTPS and Encryption: Mandatory Protection

Even when using a reliable proxy provider, proper encryption setup is critically important. Let's discuss how to ensure maximum traffic protection.

Always Use HTTPS Versions of Sites

This is a basic rule that protects against most MITM attacks. When working through proxies, it is especially important to:

• Manually enter https:// in the address bar when first visiting a site
• Check for the padlock in the browser's address bar
• Install the HTTPS Everywhere extension (for regular browsers) or ensure that automatic redirection to HTTPS is enabled in the anti-detect browser
• Never ignore warnings about certificate issues

SOCKS5 vs HTTP/HTTPS Proxy Protocols

The choice of proxy protocol directly affects security:

HTTP/HTTPS Proxies: Operate at the HTTP protocol level, can modify requests and responses. Theoretically more vulnerable to MITM attacks, as the proxy server "understands" the content of the traffic.

SOCKS5 Proxies: Operate at a lower level, simply redirect TCP connections without analyzing the content. More secure, as the proxy does not see what is being transmitted within the encrypted HTTPS connection.

Recommendation for working with sensitive data (advertising accounts, client profiles): use SOCKS5 proxies. Most anti-detect browsers (Dolphin Anty, AdsPower, Multilogin) support this protocol.

Additional Encryption: VPN on Top of Proxy

For maximum security, you can use a VPN + proxy combination. The working scheme:

1. You connect to the VPN — all traffic is encrypted
2. Through the VPN tunnel, you connect to the proxy
3. The proxy redirects traffic to the target site

This scheme protects even against a compromised proxy — the attacker will only see encrypted VPN traffic but will not be able to decrypt its content.

However, there is a nuance: some platforms (Facebook, Google) may react negatively to VPN + proxy, considering it suspicious activity. Use this method for particularly sensitive operations, but not for everyday work with advertising accounts.

Setting Up Security in Anti-Detect Browsers

Anti-detect browsers are the main tool for arbitrageurs and SMM specialists for multi-accounting. Proper security setup in them is critically important for protection against MITM attacks.

Proxy Setup in Dolphin Anty

Dolphin Anty is one of the most popular anti-detect browsers among arbitrageurs. Step-by-step setup for a secure proxy connection:

1. Creating a Profile: When creating a new profile, go to the "Proxy" section
2. Choosing a Protocol: Select SOCKS5 instead of HTTP — this will provide basic protection against interception
3. Entering Data: Enter IP:PORT:LOGIN:PASSWORD from your proxy provider
4. Checking: Be sure to click "Check Proxy" — Dolphin will show the IP, geolocation, and type of proxy
5. WebRTC: In the profile settings, set WebRTC to "Altered" or "Disabled" — this will prevent leaking your real IP
6. DNS: Ensure that DNS requests go through the proxy, not directly (setting "Use proxy for DNS")

Proxy Setup in AdsPower

AdsPower offers advanced security settings:

1. Open profile settings → "Proxy Settings" tab
2. Select "SOCKS5" as the proxy type
3. Enable the "Proxy DNS" option — all DNS requests will go through the proxy
4. In the "Advanced" section, enable "Block WebRTC" to prevent IP leaks
5. Use the built-in proxy check before saving the profile

Checking for IP and DNS Leaks

After setting up the proxy, be sure to check the profile for leaks. Even a properly configured proxy may have vulnerabilities at the browser level:

1. Open the profile with the configured proxy
2. Go to a leak check site: whoer.net or browserleaks.com
3. Check that the proxy IP is displayed, not your real IP
4. In the "WebRTC" tab, ensure that your real IP is not visible
5. In the "DNS" tab, check that the DNS servers correspond to the proxy's geolocation

Profile Isolation to Minimize Risks

Even if one proxy is compromised, proper profile isolation minimizes damage:

• One Proxy = One Profile: Never use one proxy for multiple advertising accounts
• Different Providers for Critical Accounts: Don't put all your eggs in one basket — use proxies from 2-3 different providers
• Separate Proxies for Financial Transactions: Make budget top-ups and withdrawals through a separate, maximally secured proxy
• Proxy Rotation: Periodically change proxies for accounts (every 1-3 months)

Additional Data Protection Measures

In addition to choosing the right proxy and setting up anti-detect browsers, there are additional measures that will enhance your protection against MITM attacks.

Two-Factor Authentication (2FA)

Even if an attacker intercepts your password through a compromised proxy, 2FA significantly complicates their access to the account:

• Enable 2FA on all advertising accounts (Facebook Business Manager, Google Ads, TikTok Ads)
• Use authentication apps (Google Authenticator, Authy) instead of SMS — SMS can be intercepted
• For client accounts in SMM, insist on enabling 2FA
• Store 2FA backup codes in a secure place (password manager, not in the cloud)

Password Managers with Encryption

A password manager addresses two security tasks:

1. Unique Passwords: A complex password for each account. If one account is compromised, the others remain safe
2. Auto-Fill: The password manager automatically fills in data only on legitimate sites. If you land on a phishing page through a MITM attack, the manager will not fill in the password

Recommended password managers: 1Password, Bitwarden, KeePass (for paranoids — stored locally).

Monitoring Suspicious Activity

Set up alert systems for suspicious activity in your accounts:

• Facebook Business Manager: Enable email notifications for logins from new devices, changes in payment methods, creation of new advertising campaigns
• Google Ads: Set up alerts for unusual spending and changes in account settings
• Regular Checks: Check the login history of accounts weekly — are all IP addresses yours?
• Financial Monitoring: Enable SMS notifications from the bank for any transactions with cards linked to advertising accounts

Separation of Work and Personal Data

Never mix work accounts (through proxies) and personal data:

• Use separate emails for advertising accounts
• Separate virtual cards for topping up advertising budgets (not the main card)
• Do not log into personal accounts through work profiles in the anti-detect browser
• Store passwords for personal and work accounts in different vaults

This will limit damage if a work proxy turns out to be compromised — the attacker will only gain access to work data, but not to your personal finances and accounts.

Regular Security Audits

Conduct a monthly security audit of your infrastructure:

1. Check all active proxies for leaks (whoer.net, browserleaks.com)
2. Check the login history in all advertising accounts
3. Change passwords on critical accounts (every 3 months)
4. Check for any new reviews about your proxy provider (especially negative ones)
5. Update anti-detect browsers to the latest versions

Checklist for Safe Work via Proxies

Save this checklist and verify it when setting up each new profile or changing proxy providers:

Conclusion

Protecting against MITM attacks when working through proxies is not a one-time setup, but a continuous process. You have learned how to choose a reliable proxy provider, properly set up encryption, protect anti-detect browsers, and implement additional security measures. The main thing is not to skimp on security and always check proxies before using them for valuable accounts.

Remember: losing one Facebook Ads account with a history can cost hundreds of dollars, and leaking data from client accounts in SMM can damage the reputation of the entire agency. Investments in quality proxies and proper security setup pay off many times over.

If you plan to work with advertising accounts or multi-accounting on social networks, we recommend using residential proxies — they provide a high level of anonymity and minimal risk of blocks. For working with mobile platforms (Instagram, TikTok), the optimal choice will be mobile proxies, which mimic real users of mobile operators and practically do not raise suspicions with anti-fraud systems.