Pi-Hole: A Powerful Anti-Spy Solution for Raspberry Pi

In many countries, government and private organizations often use advanced spyware, such as Pegasus, against journalists, activists, or members of various minorities. These groups have very limited means of self-defense, but one method—DNS filtering—can provide significant protection against surveillance and spying. This tool is called Pi-Hole, and in this article, we’ll look at how it works and evaluate its real-world effectiveness.

What Do You Need for Pi-Hole and How Do You Set It Up?

To create a digital barrier using Pi-Hole, you’ll need a Raspberry Pi 4 microcomputer with any amount of RAM. These devices are available on sites like AliExpress and various marketplaces, often with fast shipping. As of October 2023, prices range from $70 to $130. It’s usually more cost-effective to buy a kit that includes a microSD card, power adapter, and other accessories.

Setting up Pi-Hole is easier than it might seem, but you’ll still need some technical knowledge to install the operating system, use the command line to deploy the software, and configure your router. There are plenty of detailed guides online in both English and Russian. The method itself isn’t fundamentally new, but here we’ll focus on the practical aspects of using Pi-Hole.

Installing the operating system on a microSD card usually takes just a few minutes. For the initial setup, you might need a monitor and input devices, but you can also connect remotely via SSH.

In the terminal, installing Pi-Hole is just a matter of copying a few commands, pressing “OK,” and selecting some options.

The only real challenge may be setting up a static IP address and linking DNS requests to it. You should also choose strong passwords for both the Raspberry Pi OS and Pi-Hole itself to minimize the risk of external interference.

Using Pi-Hole: Real-World Experience

After installing Pi-Hole, you can access its settings panel through the device’s IP address in your web browser. The Pi-Hole interface is clear, informative, and quite elegant.

People often worry that such a network filter will slow down their home network, but this is a misconception. Even a Raspberry Pi 4 with just 2GB of RAM is more than enough to provide high throughput.

Blocklists

What do “yellowwildtiger.com,” “yummyfoodallover.com,” “whereismyhand.com,” and “mysuperheadphones.co” have in common? These and many other domains have been used for zero-day exploits or to deliver malicious payloads, including spyware from NSO Group. This extensive network of domains was discovered by Amnesty International’s security lab in 2021.

Pi-Hole uses third-party blocklists to block ads, often containing thousands or even tens of thousands of domains. A small blocklist is included with Pi-Hole by default, but you shouldn’t rely on it alone if you want effective protection. The best blocklists should be chosen based on your region, activities, and other factors—and should be updated regularly.

The Pi-Hole community has developed many blocklists, including special lists to block Pegasus spyware. However, attackers often create new domains for their attacks, so outdated lists won’t protect you from future versions of Pegasus or other spyware.

Resources like firebog.net offer dozens of regularly updated blocklist collections, though they may focus more on international domains. In Russian-speaking communities, you can also find updated blocklists, though it may take some effort.

You can enable a dozen or more different lists at once, filtering hundreds of thousands of domains used for ads, malware, phishing, or online tracking.

However, privacy sometimes comes at a cost. Some websites may not like that you’re blocking their ads and may bombard you with intrusive notifications or even restrict access to content. This isn’t much different from using a browser ad blocker, though disabling a rule for a specific site may take more time with Pi-Hole.

While Pi-Hole can effectively protect your home network, once you leave home, your smartphone connects to regular cellular networks, and your carefully built protection disappears.

It might seem like a dead end, but there’s a solution: you can configure Pi-Hole for remote access over the Internet. However, this can introduce noticeable delays when accessing websites, and if real hackers target you, they’ll be happy to have remote access to your security filter.

In any case, remember that DNS filtering is not a comprehensive security solution, so you shouldn’t rely solely on this method for protection.

Pros and Cons of Pi-Hole

Let’s summarize the main advantages and disadvantages of this DNS filtering technology.

Pros

• Pi-Hole is a single solution for all your home devices, covering everything from smart TVs and robot vacuums to receivers, smart bulbs, kettles, and more.
• Devices protected by Pi-Hole will no longer display ads.
• Such restrictions significantly narrow the attack surface for hackers.
• You get a convenient tool for monitoring the activity of all your devices with detailed statistics and logs.
• Your ISP will no longer see your browsing history (and pairing Pi-Hole with a VPN provides the best privacy).

Cons

• If you’re not an IT specialist, setting up Pi-Hole can be complicated and time-consuming, and you might make mistakes that leave security gaps.
• Pi-Hole may accidentally block legitimate content. At the same time, you probably won’t want to sift through hundreds of entries in your blocklists to find the culprit.
• No protection outside your home, except for remote access, which reduces both security and connection speed.
• Pi-Hole does not block malicious scripts on websites.

Bottom Line: Is Pi-Hole Enough to Protect Against All Threats?

Even after setting up multiple ad filter lists, the end result was less filtering than with a simple browser ad blocker. This is because browser-level filtering provides a deeper level of blocking, including various scripts.

However, Pi-Hole can still be useful, since you probably don’t have ad blockers for your TV or smart fridge—devices that, while unlikely, could still be used as attack vectors by determined hackers.

While Pi-Hole can limit tracking, it’s not designed to block third-party cookies, which you’ll need to handle separately.

For truly comprehensive privacy and secure access to your personal resources, you should follow all aspects of cyber hygiene: use strong passwords, enable multi-factor authentication on all critical accounts, keep your software updated, use encryption, firewalls, antivirus programs, trusted software, secure browsers, and VPNs, and always use secure communication channels.

You should also be cautious with suspicious links, emails, or messages, and never use public Wi-Fi hotspots, charging stations, or other public devices.

Even then, you won’t be 100% protected, as new vulnerabilities and attack methods appear every day.

Until a reputable cybersecurity company offers a truly comprehensive solution that combines all these protective measures in one package with security guarantees and regular updates, the best you can do is combine all the methods mentioned above.