How to Check Proxies for Malware and Viruses: 7 Ways to Protect Your Business from Data Leaks

Using infected proxies is one of the most dangerous threats for arbitrage specialists, SMM professionals, and e-commerce business owners. Malware in proxy servers can intercept logins from Facebook Ads accounts, steal credit card data, inject malicious code into your traffic, or use your connection for DDoS attacks. In this guide, we will explore practical methods for checking proxies for viruses and malware that can be applied even without technical skills.

Why Infected Proxies Are Dangerous for Business

When you connect to a proxy server, all your internet traffic passes through it. If the proxy is infected with malware or controlled by fraudsters, the consequences can be catastrophic for your business. Here are the real threats faced by users of infected proxies:

Main Threats of Infected Proxies:

• Credential Theft — interception of logins and passwords for Facebook Ads, Google Ads, TikTok Ads, Instagram, bank accounts
• Interception of Cookies and Authorization Tokens — attackers gain access to your accounts without needing to know passwords
• Injection of Malicious Code — modification of web pages on the fly: changing payment details, injecting crypto miners
• Credit Card Data Theft — interception of information during ad payments or purchases
• Man-in-the-Middle Attacks (MITM) — decryption of HTTPS traffic through fake SSL certificates
• Using Your IP for Attacks — your proxy can be used for DDoS, spamming, hacking
• Leakage of Confidential Information — advertising campaign strategies, creatives, client lists

Free public proxies and proxies from unverified providers with suspiciously low prices are particularly dangerous. According to Symantec research, up to 79% of free proxy servers are either infected with malware or actively intercept user data.

Signs of an Infected Proxy Server

Before moving on to technical verification methods, it is important to know the obvious signs that a proxy may be infected or compromised. If you notice at least one of these symptoms — immediately stop using the proxy and conduct a full check.

If you are working with Facebook Ads, Google Ads, or TikTok Ads accounts through anti-detect browsers (Dolphin Anty, AdsPower, Multilogin), pay special attention to browser security warnings. Modern anti-detect browsers have built-in mechanisms for detecting suspicious proxy activity.

Checking IP Reputation and Blacklist

The first and simplest way to check a proxy is to analyze the reputation of its IP address. If the proxy's IP is on blacklist lists or has a poor reputation, it may indicate that it has been used for malicious activity or has been compromised.

Step 1: Find Out the Proxy's IP Address

Connect to the proxy and open one of the IP checking services:

• 2ip.ru — shows your current IP, location, provider
• whoer.net — detailed IP analysis with anonymity rating
• ipleak.net — checking for DNS, WebRTC, IPv6 leaks

Write down the IP address shown by these services — this is your proxy's IP.

Step 2: Check the IP in Blacklist Databases

Use specialized services to check the IP for presence in blacklists:

How to Interpret the Results:

• 0 blacklists — a good sign, the IP is clean
• 1-2 blacklists — possible false positives, further verification needed
• 3+ blacklists — high risk, the IP has been used for spam or attacks
• 10+ blacklists — critical level, the proxy is dangerous to use

Step 3: Check IP History via AbuseIPDB

AbuseIPDB shows a detailed history of complaints against the IP address. Go to abuseipdb.com, enter the proxy IP, and review:

• Confidence of Abuse — percentage of confidence in abuses (over 50% — a bad sign)
• Reports — number of complaints (over 10 complaints — a reason to be cautious)
• Categories — types of abuses: DDoS, spam, brute force, malware distribution
• Last reported — date of the last complaint (if recent — the IP is actively used for attacks)

Traffic Analysis Through Proxies: Searching for Suspicious Activity

One of the most reliable ways to detect malware in proxies is to analyze network traffic. Infected proxies often inject additional requests, modify data, or redirect traffic to malicious servers. This method does not require deep technical knowledge — there are simple tools with graphical interfaces available.

Method 1: Using Wireshark (for Advanced Users)

Wireshark is a free network packet analyzer. Download it from wireshark.org and install it.

Step-by-step Instructions:

1. Launch Wireshark and select the active network interface
2. Click "Start capturing packets" (the blue shark button)
3. Connect to the proxy through a browser or anti-detect (Dolphin Anty, AdsPower)
4. Open several regular websites (Google, Facebook, YouTube)
5. Stop capturing packets after 2-3 minutes
6. Apply the filter: http or dns

What to Look For:

• Suspicious DNS Requests — requests to unknown domains, especially with short random names
• Unencrypted HTTP Requests — data transmission without HTTPS to suspicious addresses
• Multiple Connections to One IP — may indicate a command-and-control server for malware
• Strange User-Agent Strings — if they do not match your browser
• Large Data Transfers — with minimal activity may indicate data leakage

Method 2: Using GlassWire (Simple Option for Beginners)

GlassWire is a user-friendly firewall with visual traffic monitoring. The free version is available at glasswire.com.

How to Use:

1. Install GlassWire and start monitoring
2. Connect to the proxy
3. Work normally for 10-15 minutes
4. Open the "Things" tab in GlassWire — this shows all applications using the network
5. Check the "Firewall" tab — list of all network connections

Red Flags:

• Unknown applications actively transmitting data
• Connections to IP addresses in countries you do not work with (especially China, Russia, Ukraine for Western services)
• Sharp traffic spikes without visible reason
• Connections on non-standard ports (not 80, 443, 8080)

Method 3: Checking Through Online Traffic Analysis Services

There are specialized online tools for testing proxies:

These services will automatically check the proxy against multiple security parameters and provide an overall score. A score below 50/100 is a reason to refrain from using the proxy.

Scanning Proxies with Antivirus Tools

Modern antivirus and anti-malware scanners can detect infected proxy connections in real-time. This method is especially effective for identifying known malware signatures and behavioral anomalies.

Recommended Tools for Checking

How to Check Proxies Using Malwarebytes (Step-by-Step)

1. Download and install Malwarebytes from the official website (malwarebytes.com)
2. Launch the program and update the virus signature databases
3. Connect to the proxy server through a browser or anti-detect browser
4. In Malwarebytes, go to "Scan" → select "Threat Scan"
5. Actively use the internet through the proxy during the scan (open 10-15 different websites)
6. Wait for the scan to complete (usually 5-10 minutes)
7. Review the results — Malwarebytes will show detected threats

If Malwarebytes detects threats in the categories "Trojan.Proxy", "PUP.ProxyBundler", "Backdoor", "Spyware" — immediately disconnect from the proxy and change all passwords for important accounts.

Enabling Real-Time Protection

For continuous monitoring of proxy connections, enable real-time protection features:

• Kaspersky: Settings → Protection → Network Protection → enable "Network Activity Monitoring"
• Bitdefender: Protection → Advanced Threat Defense → enable
• Norton: Settings → Firewall → Advanced → enable "Intrusion Prevention"

These features will automatically block suspicious proxy activity and alert you to potential threats.

Checking for DNS Leaks and WebRTC Leaks

DNS leaks and WebRTC leaks are common vulnerabilities that can expose your real IP address even when using a proxy. Attackers often deliberately configure proxies with leaks to collect real user data. For arbitrage specialists and SMM professionals, this is critical — leaking your real IP can lead to linking all your Facebook, Instagram, or TikTok accounts.

Checking for DNS Leaks

A DNS leak occurs when DNS requests are sent through your real internet provider instead of through the proxy. This allows tracking of your activity and determining your real location.

How to Check:

1. Connect to the proxy through a browser or Dolphin Anty / AdsPower
2. Open the site dnsleaktest.com
3. Click the "Extended test" button
4. Wait for the results (30-60 seconds)

Interpreting the Results:

• ✅ No Leaks: all DNS servers belong to the proxy provider or are located in the same country as the proxy IP
• ⚠️ Partial Leak: some DNS requests go through your real provider — requires configuration
• ❌ Full Leak: all DNS servers show your real provider — the proxy is not functioning or is misconfigured

Checking for WebRTC Leaks

WebRTC is a technology for video/audio communication in the browser. It can expose your real IP even when using a proxy, bypassing it through a direct P2P connection.

How to Check:

1. Connect to the proxy
2. Open the site browserleaks.com/webrtc
3. Examine the "Your IP Addresses" section

What Should Be:

• Public IP Address: should match the proxy IP
• Local IP Address: may show a local IP (192.168.x.x or 10.x.x.x) — this is normal
• SHOULD NOT BE: your real public IP in the list

If browserleaks shows your real IP — this is a critical vulnerability. Solution:

• In a regular browser: install the "WebRTC Leak Shield" or "uBlock Origin" extension with WebRTC blocking
• In Dolphin Anty / AdsPower: enable "Block WebRTC" or "Replace WebRTC IP" in the profile settings
• In Firefox: open about:config → find media.peerconnection.enabled → set to false

Comprehensive Check for All Leaks

For a complete check of the proxy for all types of leaks, use the service ipleak.net. It checks simultaneously:

• IP address (IPv4 and IPv6)
• DNS leaks
• WebRTC leaks
• Geolocation by IP
• Browser and system information

If ipleak.net shows only the IP and proxy data, without your real information — the proxy is configured correctly and is safe to use.

Checking SSL Certificates and MITM Attacks

Man-in-the-Middle (MITM) attacks through proxies are one of the most dangerous scenarios. An attacker intercepts your HTTPS traffic, decrypts it using a fake SSL certificate, and gains access to logins, passwords, and credit card data. For arbitrage specialists, this means losing access to advertising accounts worth tens of thousands of dollars.

How MITM Attacks Work Through Proxies

A typical scenario: you connect to a proxy and open facebook.com. An infected proxy:

1. Intercepts your request to facebook.com
2. Connects to the real facebook.com via HTTPS
3. Receives data from Facebook
4. Creates a fake SSL certificate for facebook.com
5. Returns data to you with the fake certificate
6. Reads all your traffic in plain text (logins, passwords, messages)

Modern browsers should warn about fake certificates, but some proxies use clever methods to bypass this protection.

Manual SSL Certificate Check

Step-by-step Instructions for Chrome / Edge:

1. Connect to the proxy
2. Open an important site (facebook.com, google.com, bank site)
3. Click on the lock icon to the left of the address bar
4. Select "Connection is secure" → "Certificate is valid"
5. Examine the certificate:
   • Issued to: must exactly match the site's domain
   • Issued by: must be a known certificate authority (Let's Encrypt, DigiCert, Google Trust Services)
   • Valid from / to: check the dates — the certificate should not be expired

Red Flags (Signs of MITM):

• The certificate is issued by an unknown organization or self-signed
• Issued by contains strange names like "Proxy CA", "MITM Certificate", name of the proxy provider
• Certificate issue date — today or a few days ago (real certificates are updated less frequently)
• The browser shows a warning "Your connection is not private" (NET::ERR_CERT_AUTHORITY_INVALID)

Automatic Check Using Online Tools

Use the service badssl.com to test the browser's response to various SSL issues:

1. Connect to the proxy
2. Open badssl.com
3. Try to open test pages:
   • expired.badssl.com — the browser should show a warning
   • wrong.host.badssl.com — there should be a warning
   • self-signed.badssl.com — there should be a warning

If the browser does NOT show warnings on these test pages — the proxy is interfering with SSL traffic and substituting certificates. This is a dangerous proxy.

Protection Against MITM in Anti-Detect Browsers

If you are using Dolphin Anty, AdsPower, or Multilogin for working with advertising accounts:

• Dolphin Anty: Settings → Security → enable "Check SSL certificates" and "Block insecure connections"
• AdsPower: Profile settings → Advanced → enable "Strict SSL certificate verification"
• Multilogin: by default has strict certificate verification, no additional settings are required

These settings will block connections to the proxy when suspicious SSL certificates are detected.

How to Check the Reliability of a Proxy Provider

The most effective way to avoid infected proxies is to work only with verified providers. Even if technical checks show that the proxy is clean now, an unreliable provider can start intercepting data or sell access to servers to third parties at any moment.

Criteria for Evaluating a Proxy Provider

Where to Find Reviews About Providers

Before purchasing a proxy, be sure to study independent reviews:

• Reddit: subreddits r/proxies, r/AffiliateMarketing, r/FacebookAds — arbitrage specialists share experiences
• Trustpilot: verified reviews with purchase confirmation
• Arbitrage Forums: Affbank, Affiliate.World — discussions about proxy providers
• Telegram Channels: channels about arbitrage and SMM often publish reviews
• YouTube: reviews from experienced arbitrage specialists and SMM professionals

Trial Period — A Must

Never purchase proxies for a long term without testing. Reliable providers always offer:

• Trial Period — 1-3 days of free testing
• Money-back Guarantee — refund within 24-48 hours
• Minimum Package — the option to buy 1-5 GB to check quality

During the trial period, conduct all checks from this article: blacklist, DNS leaks, SSL certificates, antivirus scanning.

Rules for Safe Proxy Usage

Even if the proxy has passed all checks and is deemed safe, follow cyber security rules to minimize risks.