Stop Ignoring Botnets: Alarming Security Flaws Are Leaving You Vulnerable

About The Author – Stop Ignoring Botnets: Alarming Security Flaws Are Leaving You Vulnerable

I recently wrote about how bots wreak havoc on our applications through methods like credential stuffing and credit card BIN surfing. After that article, several people asked me how these bots operate. In this post, I want to share my journey delving into the world of bots—what they are, how they work, and why so many exist today.

When I first heard the term “bot,” I assumed it was shorthand for “robot.” In cybersecurity, a bot typically refers to an automated application that can run continuously without human interaction. Bots operate across the internet, carrying out legitimate tasks (like web indexing) and malicious (like spreading malware or attacking websites).

Early on, many malicious bots were installed on compromised servers or personal computers. Attackers used them to form botnets—networks of infected machines all controlled remotely. Over time, antivirus and anti-malware solutions became more effective at detecting and removing these infections. However, cybercriminals adapted. They turned their attention to a new frontier with fewer security safeguards: the Internet of Things, often called IoT.

IoT devices include (but aren’t limited to) things like:

• Streaming boxes
• Smart
  • speakers
  • light switches
  • plugs
  • thermostats
  • smoke detectors
  • blinds
  • door locks
  • alarms
  • lights

This list seems endless, and research often cites IoT devices that count well into the billions—some estimates put that number around 18.8 billion or more worldwide. Because these devices are always connected and sometimes lack robust security measures, they’re attractive targets for cybercriminals looking to assemble powerful botnets. Once compromised, these IoT devices can be directed to perform coordinated attacks, steal data, or send spam—all without the owner’s knowledge.

As someone who has explored the growth of IoT botnets, I’ve seen firsthand how vulnerable network-connected gadgets can be if they aren’t correctly secured. Moving forward, manufacturers and consumers alike must prioritize better security practices. Strong passwords, frequent firmware updates, and careful network configuration can go a long way toward making IoT devices less susceptible to attacks.

When I first examined how attackers turn IoT devices into weapons, I discovered just how unregulated the IoT space can be. Many devices lack consistent security measures right out of the box. While I’m not saying every IoT gadget is vulnerable, many can easily compromise and install malicious code, especially if security wasn’t a priority during development.

From my perspective, the problem starts with the drive to get products to market as quickly as possible. Some startups avoid thorough testing or advanced security features because they fear slowing their launch. In other cases, manufacturers worry that installing complex security controls could create issues with remote updates, which might lead to massive recalls if something goes wrong. Unfortunately, these choices weaken our digital environment and offer attackers an open door.

I’ve seen firsthand how these devices can become part of a botnet. Bots perpetually scan IP ranges, searching for open ports. If a device is exposed on the internet—mainly using default credentials—it’s an easy target. You might wonder, “What if I hide my gadgets behind a home router?” Sadly, there are still ways for attackers to reach them. Let me share two common methods:

1. Compromised Update Servers
   Many IoT devices constantly “phone home” to the manufacturer’s servers for updates. If attackers infiltrate or spoof these servers, they can push a malicious firmware update. Once installed, it’s game over—the device is compromised.
2. UPnP and Port Forwarding
   I’m all for convenience but features like UPnP (Universal Plug and Play) can be a double-edged sword. UPnP automatically opens ports on your firewall so devices can receive direct inbound connections; if a hacker finds that open port, they can slip inside your network and plant malware without your knowledge.

Because IoT gadgets have exploded in popularity, these flaws can quickly spread an attack over countless devices. From there, it’s only a matter of time before attackers turn an army of compromised cameras, doorbells, or light switches into a botnet capable of massive DDoS attacks, data theft, or worse.

When I first started learning about botnets, I assumed I’d easily spot any suspicious activity on my home or small business network. The reality is more nuanced—some botnets give themselves away, while others do everything they can to stay hidden.

For example, if a botnet aggressively searches for new, vulnerable hosts, I can often detect it with a honeypot. I’ve set these up in my environment to lure in malicious traffic. You can install free software-based honeypots or upgrade to a router or gateway with honeypot features. For instance, Ubiquiti’s Dream Machine lineup has built-in capabilities that can help you monitor and detect unusual traffic patterns at a reasonable price.

However, not all botnets behave this way. Some remain dormant until they receive instructions from the attacker. These botnets produce very little network traffic, making them tough to spot with traditional tools. Attackers know that all their hard work is lost if their botnet is discovered. That’s why they often infect as many devices as possible and then limit each to just a handful of daily requests. This minimal usage blends with regular IoT traffic and can slip under the radar.

I learned that an IoT device transmitting under 1 MB of data per day isn’t likely to stand out on most consumer networks. That means a low-traffic botnet might operate in the background for weeks or months before anyone notices. As a result, it’s crucial to regularly check your devices and network for anything unusual, update your firmware, and adopt security best practices so you aren’t caught off guard.

If you’re running a small online business, it might appear as waves of legitimate transactions from around the globe. On the surface, it’s just traffic, but behind the scenes, it’s engineered to overwhelm your website’s capacity to handle orders or payments.

If the botnet is designed to knock you offline completely, you’ll likely see a SYN flood attack. In my experience, that means the botnet bombards your server with so many “synchronization” requests that it maxes out your resources. Suddenly, no genuine customer can connect because the server is flooded with fake connection attempts.

I’ve noticed a different pattern for home users: constant port scanning that checks if you have features like UPnP (Universal Plug and Play) turned on or any open ports that weren’t protected by your firewall. Attackers rely on these scans to discover if they can break in and add your devices to their botnet.

From fake transactions to denial-of-service attempts, a botnet can assault you in many ways. By staying vigilant—monitoring network traffic, patching devices, and using robust security measures—you can lower your risk of becoming a target.

There’s no perfect, one-size-fits-all solution. Honestly, the only guaranteed way to avoid botnets is not to own any IoT devices at all. But let’s face it, in today’s connected world, that’s not practical. Even if you skip smart gadgets, attackers can still plant malware on your computer or phone.

Fortunately, I’ve found a few simple precautions that significantly reduce the odds of hosting a botnet on your network:

1. Disable UPnP
   Many home routers have Universal Plug and Play (UPnP) enabled by default, which makes it easy for devices to open ports automatically. Turn this off immediately so there’s less risk of unwanted traffic flowing into your network.
2. Avoid Port Forwarding
   Unless there is a specific reason—like hosting a game server, don’t forward ports on your home router. This approach limits the attack surface for malicious actors trying to slip in.
3. Use a Separate Wi-Fi Network for IoT
   Set devices up on a guest or separate Wi-Fi network with device isolation enabled. If one device gets compromised, it can’t spread malware to your computers or other critical devices.

While no solution is foolproof, basic measures like these make it much harder for attackers to turn your devices into their bot army.