When Your IoT Devices Attack: The Pre-Emptive Security Fix for Industrial Routers

The New Attack Surface: Why Your Latest Phishing Text Came from a Traffic Light

The latest widespread SMS phishing (aka smishing) campaign, recently highlighted by Ars Technica, is a great example of how hackers are no longer just using botnets of PCs; they are also weaponizing easily accessible Industrial IoT (IIoT) devices.

Specifically, security researchers discovered that thousands of cellular routers used to connect critical infrastructure like power meters and utility systems, were being exploited to blast mass phishing messages.

This attack is not a tale of a sophisticated zero-day. It’s a story of a common yet avoidable security failure rooted in simple, critical architectural flaws:

1. Exposed Assets - Over 18,000 industrial routers were internet-accessible, with hundreds allowing direct, unauthenticated access to their programming APIs.
2. Weak/Exposed Authentication Barrier - Because these devices were exposed with open ports, hackers could remotely send commands to the routers' APIs—which control the cellular SIM cards—allowing them to mass-send smishing texts globally.

In short, the devices were exposed, and their core functionality (sending texts) was left wide open to anyone who cared to look.

The Failure of Traditional Perimeter Security

This incident is just another example of where perimeter-based security, firewalls, VPNs, and proxies, didn’t work. Why? Because the devices open ports exposed on the Internet, allowing the attacker to initiate a connection. Once that connection was established, the attacker only needed to exploit the lack of secure authentication on the device's API.

The problem isn't the phishing text itself; the problem is the architecture that allowed the criminal infrastructure to be built on top of critical assets.

The Solution: Pre-Emptive Security and Zero Trust Invisibility

The only way to defend against this kind of weaponization is through a strategy of Preemptive Security, an architectural shift that focuses on neutralizing the threat before an attack can even begin. For NoPorts, this means making the asset invisible to external threats and strictly enforcing identity before the network connection is ever established.

Here’s how the NoPorts Zero Trust Architecture closes this vulnerability:

1. Attack Surface Elimination - NoPorts starts by creating a secure two way tunnel without need of an open, exposed port on the router or the device that is authorized to connect to it. By never opening an inbound port, the industrial router becomes invisible to the external port scanners used by criminals. If a criminal can't see the router on the internet, they cannot target its vulnerable API.
2. Authentication Before Connection - Unlike systems where the connection is established and then the local API attempts authentication, NoPorts enforces cryptographic authentication prior to any connection to the device. Only a cryptographically verified and authorized user or device is granted a tunnel to the router. An attacker cannot simply exploit an unauthenticated command, because they are not allowed to connect to the device in the first place.
3. Micro-segmentation - Even if an authorized technician were to connect, the Zero Trust policy ensures they only have access to the specific API endpoint or command they need, restricting lateral movement or misuse of the device's cellular function.

The lesson from the IIoT smishing campaign is clear: If your critical assets have open ports, they are not secure; they are potential weapons. Pre-emptive Security, driven by a Zero Trust architecture that authenticates first, ensures that industrial infrastructure remains a defense asset, not an attack vector.

Ready to stop managing attack surfaces and start eliminating them? Explore the NoPorts Use Case for IoT Access & Privacy and try our platform for free.