How botnets threaten devices and online privacy

A botnet is one of the most powerful tools in a hacker’s arsenal: it turns your own device into a weapon, often without your knowledge. Understanding what a botnet is, how it spreads, and how it’s used in cyberattacks is key to protecting your privacy and keeping control of your digital life.

What Is a botnet?

A botnet — short for “robot network” — is a group of internet-connected devices that have been infected with malware and are being remotely controlled by an attacker, often called a botmaster. Once compromised, these devices — called bots or zombies — operate in unison to carry out cyberattacks or other unauthorized activities, usually without the owner's knowledge.

Botnets can include a wide variety of devices, such as:

• Laptops and desktop computers

• Smartphones and tablets

• Smart home devices like routers, cameras, and thermostats

• Enterprise servers and cloud infrastructure

Botnets are most commonly used to launch large-scale Distributed Denial of Service (DDoS) attacks, send spam, steal personal data, or spread additional malware. Unlike traditional malware, a botnet doesn't just infect a single device — it turns your device into part of a much larger, automated network designed to do harm. Be sure to check your iPhone for malware periodically.

Because botnets rely on high-volume, coordinated traffic, they pose a serious threat to both individual privacy and the stability of online infrastructure. And because infected devices often behave normally on the surface, most users never realize they’ve become part of one.

How do botnets work?

Botnets are typically built and controlled through a series of coordinated steps. Here’s how they function:

Infection

The attacker deploys malware using phishing emails, fake downloads, or unpatched vulnerabilities. Once opened, the malicious software installs silently and begins operating in the background. IoT devices with default credentials are frequent targets.

Connection

After infection, the device "phones home" to the botnet operator. It either connects to a central command-and-control (C2) server or uses a peer-to-peer (P2P) model, staying online and ready to receive instructions at any time.

Execution

The attacker sends commands to all infected bots, often using automation. These can include launching DDoS attacks, stealing login data, mining cryptocurrency, or scanning for more vulnerable devices to expand the network.

Evasion

Modern botnets use sophisticated evasion techniques, like encryption, domain generation algorithms (DGAs), or fast-flux DNS to avoid detection. These methods make them difficult to block or shut down using traditional cybersecurity tools.

How to protect yourself from botnets

You don’t need advanced tools to reduce your exposure. These practical steps help harden your devices against being infected or recruited into a botnet.

Keep devices updated

Update your operating systems, apps, firmware, and router software regularly. Many botnets exploit known vulnerabilities that have already been patched — so staying current is one of the simplest ways to block entry points.

Use strong, unique passwords

Create long, complex passwords for every device and online account. Never reuse passwords across services, and change the default credentials on smart devices, which are often exploited in large-scale botnet attacks.

Install trusted security tools

Run antivirus and anti-malware software on your phone, computer, and router. These tools can detect botnet malware, block suspicious behavior, and alert you if your device becomes part of a malicious network.

Avoid suspicious links and downloads

Most botnet infections start when users click on phishing links, download fake software, or install compromised browser extensions. Only download apps and files from trusted sources like official app stores or vendor websites.

Disable unused services

If you’re not using features like Bluetooth, UPnP, or remote device access, turn them off. Every open port or connection increases your attack surface and gives botnet malware more ways to enter your system.

Use a privacy-focused VPN

A VPN helps shield your IP address and online activity. NymVPN goes further by protecting your metadata, traffic patterns, and connection timing, making it harder for attackers to fingerprint your device or network behavior.

Why botnets are a privacy problem — Even if you’re not the target

Even if your device isn’t being used for theft or fraud, being part of a botnet exposes you to surveillance, loss of control, and reputational damage. Attackers can capture your IP address, location, metadata, and behavior patterns — all without logging into your accounts.

Botnets also contribute to larger attacks that target activists, journalists, or infrastructure. This means that your device might be used to hurt others without your knowledge. Preventing botnet infections isn’t just about personal safety: it’s about stopping your devices from becoming part of a much broader privacy and security problem.