Why Immune · The Agentless Advantage
The advantage that covers the blind spot everyone else leaves
Ask most security vendors to protect an infusion pump or a decade-old imaging controller and they cannot, because there is nowhere to install their agent. That gap is not a minor limitation in a hospital. It is where attacks begin. Covering it is the single clearest reason hospitals choose Immune.
The medical devices attackers target most are the ones no agent can run on. Immune protects them at the network boundary — the one place they can be defended — closing a blind spot that endpoint and backup tools structurally cannot.
An entire class of systems that security forgot
Modern security has, for the most part, converged on a single model: install an agent on the device, and let that agent watch for and block threats. On laptops and servers this works well. But it contains a hidden assumption — that you can install software on the thing you want to protect — and in a hospital that assumption breaks for thousands of devices. Infusion pumps, imaging systems, patient monitors, and countless other pieces of connected medical equipment run closed or certified operating systems that do not accept third-party software. Many are years past their support date and will never receive another update. You cannot install an agent on them, and you cannot patch them. From the perspective of agent-based security, they simply do not exist.
The scale of this is hard to overstate. A large hospital may operate ten to fifteen thousand connected devices, the majority of which cannot host a security agent. Research across millions of medical devices has found that they average more than six known vulnerabilities each, that the majority of hospitals run at least one device with a vulnerability attackers are actively exploiting, and that a large share are end-of-life. This is not a rounding error in a hospital's attack surface. It is a substantial fraction of it, and it is almost entirely unprotected by the tools most hospitals rely on.
Attackers go exactly where the agents can't
None of this is lost on ransomware operators. As agent-based defenses have improved on the devices that can run them, attackers have shifted toward the ones that cannot. It is a rational move: an unmonitored medical device is a quiet place to establish a foothold, a hiding spot that raises no endpoint alarms, and a bridge toward the critical systems that make a hospital pay. The industry has an uncomfortable shorthand for this — attackers go where agents can't — and in a hospital that phrase points directly at the medical-device fleet. A defense that cannot see these devices is, in a real sense, defending only part of the building while the attacker walks in through the unwatched part.
How Immune closes it
Protect the device where it lives: on the network
If you cannot put protection on the device, you put it around the device. This is the essence of Immune's agentless advantage. Every protected device sits behind Immune's mediated network boundary, and Immune learns the normal behavior of each one — the systems it talks to, the protocols it uses, the volume and timing of its activity. Because a medical device's behavior is so consistent and predictable, a deviation stands out sharply. When a device starts reaching for systems it never touches, beaconing to an unfamiliar destination, or being used to move toward the electronic health record, Immune sees it and treats it as a high-priority signal.
The response is designed for the one thing that matters most in a hospital: patient safety. When Immune confirms a device is compromised, it quarantines the device at the network layer — it isolates the device's connectivity while leaving it powered and clinically functional. The attacker's path is severed; the patient depending on the device is not put at risk. Contrast this with a naive response that might simply shut the device down, and the importance of a purpose-built, healthcare-aware approach becomes clear. Covering the agentless fleet is not just about extending visibility; it is about doing so in a way that a hospital can actually trust.
Why this is decisive
- It closes the primary entry point that endpoint and backup tools leave wide open.
- It covers a huge fraction of the hospital's real attack surface, not a rounding error.
- It is safe by design — quarantine at the network layer, never shutting a device down.
- It is the differentiator competitors structurally cannot match with an agent-based model.
The agentless advantage is a founding reason Immune exists. See it in detail on the medical-device security page, understand how it fits the wider loop in how Immune works, and compare it against other approaches in the capability comparison.
Common questions
The agentless advantage, answered
+What is agentless protection?
Agentless protection secures a device without installing software on it, by monitoring and controlling its behavior at the network layer instead. It is the only way to protect medical devices and legacy systems that cannot host a security agent.
+Why can't security agents run on medical devices?
Most medical devices run closed, certified, or unsupported operating systems that do not permit third-party software, and a large share are end-of-life. Installing an agent is often impossible and can even void certification, so protection has to happen off the device.
+Why is the agentless gap so dangerous in hospitals?
A large hospital runs thousands of connected devices, most unable to host an agent. Attackers deliberately target these blind spots as entry points and hiding places, then pivot toward critical systems — making agentless coverage essential rather than optional.
+How does Immune protect agentless devices without disrupting them?
Immune baselines each device's normal network behavior and, on a confirmed threat, quarantines it at the network layer — cutting the attacker's access while leaving the device powered and clinically functional.
Cover the devices attackers count on you missing
Book a demo and see Immune protect an agentless medical device at the network boundary — and quarantine a threat without ever shutting it down.