What is an open proxy, and why has your IP address been flagged as one?

An open proxy is a proxy server that acts as an intermediary between the client (the user’s computer) and another server (a website or an online service). Anyone on the internet can connect to open proxies to relay their online traffic through them without any authentication or authorization.

This is where the principals of how a proxy server works come into play. Open proxies, like other proxies, forward requests and responses between clients and servers, allowing internet users to access content on the internet indirectly. They can help mask your IP address from websites and internet services you access through them, enhancing your online privacy. A reverse proxy server, on the other hand, operates in a similar manner but acts on behalf of the server rather than the client, intercepting requests from clients and forwarding them to the appropriate backend server.

An open proxy server allows internet users to browse the internet with increased privacy. When you use an open proxy, your traffic is routed through the proxy server and receives the same IP address. This means that websites you visit will see the proxy server’s IP address instead of yours. When you change your IP address, you can access your home content while abroad and bypass content filtering. It is also difficult to trace your online activities back to you, which lowers your online footprint.

Directing your traffic through a proxy server also provides a certain level of privacy from your internet service provider. Your ISP will not know what websites you visit. But keep in mind that some ISPs are against the use of proxy servers and that using one is risky.

Despite increasing your online privacy, open proxies present multiple risks. These servers allow public access and are configured to treat all traffic equally. This means they allow the transmission of both legitimate and malicious traffic. As a result, cybercriminals use proxy servers to search for potential targets, carry out botnet attacks, and flood them with spam or viruses.

Open proxies are often used by multiple users at the same time, leading to congestion, which results in slow website loading times and a frustrating user experience. Another drawback is that many network and website operators block traffic from open proxy IP addresses, making it difficult to access their content. Many ISPs and network administrators also block or restrict traffic from known open proxies because of their associations with malicious activities and online fraud.

In some cases, your IP address might be flagged as an open proxy. For example, if you open your Instagram account and get a message saying your IP has been flagged as an open proxy, it means that Instagram has blocklisted your IP. Other platforms can also mistakenly flag your IP or issue an IP ban. This happens because of multiple reasons:

• Server misconfiguration. If you use a proxy server on your network, but it is misconfigured and allows unauthorized access, ISPs, web services, online platforms, and security software could flag its IP as an open proxy.
• Malware infection or being part of a botnet. Your server or network device might be acting as an open proxy if it is infected with malware or is a part of a botnet. If cybercriminals have compromised your device, they might be using it as a proxy for their malicious activities.
• Previous misuse. If the IP address you are using has previously participated in abusive online activity, it might raise a red flag.
• A shared IP address. Websites could flag your IP as an open proxy if you’re on a shared network, like a public Wi-Fi, and share the same address with other users who use it for proxying traffic.
• Suspicious traffic patterns. If your IP address is generating a significant amount of traffic that is characteristic of an open proxy (for example, a high number of connection requests), proxy detection tools might flag it as such.

Organizations use various methods to detect open proxies. Here’s a list of the most common ones:

• Port scanning. An automated tool or service scans a range of IPs for open ports associated with open proxies.
• Traffic behavior analysis. Some systems monitor network traffic patterns and look for high traffic volumes, a large number of connection requests, and other behavioral patterns typical of proxying.
• DNS query analysis. DNS requests for domains linked to proxy services or anonymization tools might raise red flags.
• Monitoring access logs and anomalies. Access logs for web servers and network devices can show unusual traffic patterns, like a single IP making an excessive number of requests.
• Blocklists. Organizations keep lists of known open proxies and malicious IP addresses. Network administrators and security tools check these blocklists when flagging IPs that exhibit proxy-like behavior.
• Community reporting. Users and network administrators report suspicious IPs and proxy-like behavior to organizations, helping to spot open proxies.

You should check and make sure your IP is not an open proxy to maintain your online reputation and ensure your network’s security. Here’s a guide on how to do it:

• Use an online proxy checker. Multiple online proxy checkers will verify if your Ip has been flagged as an open proxy.
• Check public IP reputation lists. Find a public IP reputation list or blocklist maintained by cybersecurity organizations and ISPs and look for your address.
• Analyze your network traffic patterns for unusual behavior like a high volume of connection requests and other proxy-like activity.
• Check your server and proxy configurations to ensure they are not misconfigured to act like an open proxy.
• Contact your internet service provider if you believe your IP has been falsely flagged. Request its assistance in removing your address from the blacklist.

Disabling open proxies in your network can help you avoid security risks. Here is a step-by-step guide for Chrome users on how to avoid open proxies:

1. Click the three dots at the top right corner of the browser.
2. Open the “Settings” tab.
3. Select “System,” then “Open your computer’s proxy settings.”
4. Under the “Automatic proxy setup,” toggle the “Automatic detect settings” to Off.
5. Under the “Manual proxy setup,” toggle the “Use a proxy server” to Off.
6. Click “Save.”

Here is a similar guide for Chrome users on Mac on how to turn off access to an open proxy server:

1. Select the three dots at the top right corner of the browser.
2. Select “Settings.”
3. Select “Systems.”
4. Click “Open your computer’s proxy settings.”
5. Under the “Proxies” tab, uncheck all of the options listed.
6. Select “OK” to save the settings.

Overall, if you want to minimize the risk of using an open proxy, do not share your IP address and use private Wi-Fi networks. Ensure that your network is secure by reviewing your router and firewall settings to prevent unauthorized access. Secure your Wi-Fi networks as well by using a strong password and encryption. Use strong authentication (like 2FA) if you have network devices that you access remotely. And monitor your network traffic for unusual activity, such as a high volume of connection requests.

If you are worried about your privacy, use a reputable VPN service that will conceal your IP address and encrypt your online traffic. By maintaining a proactive approach to network security, you can avoid the risks of open proxies and minimize being mistakenly flagged as one.