Hidden Dangers in Open-Source AI Models: Why “Home Cooking” Isn’t Always Safe

WeiWei Feng
3 min readFeb 10, 2025

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I used to think that if I downloaded an open-source AI model and ran it in my own cloud within a private network or on-prem setup, it was safe — kind of like cooking at home instead of eating at a restaurant. If I control the kitchen, I control what goes into my food, right?

Well, after reading articles about evil models, I realized it’s not that simple. Open-source models can still bring hidden dangers, just like how a seemingly fresh batch of groceries could contain spoiled ingredients or even something toxic hidden inside.

The “Spoiled Pickle” Problem

Most AI models come with weight files, often stored as pickle files. Think of them like pre-packaged meals — convenient, but you don’t always know what’s inside. The problem? Pickle files can execute arbitrary code when loaded. This means a malicious actor could slip in nasty malware, which then runs the moment you “serve” the model in your system.

How to stay safe:

Just like you wouldn’t eat something from a sketchy, unsealed package, don’t blindly trust pickle files. Use security scanners to check them before use. Convert them to a safer format like SafeTensors, which is like vacuum-sealing your ingredients to prevent contamination.

The “Invisible Ink” Trick

Think about how spies hide secret messages using invisible ink. A similar trick can be done with AI models. The model’s weights (which determine how it generates responses) have millions of values — some important, some not. A hacker can subtly tweak the “unimportant” ones to embed hidden malware, just like hiding data in unnoticeable pixels of an image.

At first glance, the model looks fine. It works. It gives good responses. But the hidden malware might only activate under certain conditions — like a secret keyword or a specific request.

The “Whisper Network” Attack

This is the most advanced trick, like a secret society passing messages through subtle nods and winks instead of obvious notes. Instead of hiding malware in one small section, hackers can distribute it across the entire model, making it nearly impossible to detect or remove. These advanced attacks are sometimes designed to survive typical defenses.

Neutralizing Embedded Malware

One effective strategy to disrupt simpler hidden malware is to fine-tune or retrain the infected model. This process adjusts the model’s parameters and can break the malicious code without significantly harming the model’s performance.

Additionally, pruning or compressing a model — techniques that remove or reorganize parts of the neural network — can also disrupt certain hidden backdoors or malicious code by changing the very structure on which they rely.

Key Caveat: While fine-tuning, pruning, and compression can defeat many forms of embedded malware, extremely advanced or highly distributed attacks may survive these methods. In other words, these techniques are not guaranteed “one-stop solutions,” but they are still valuable defenses against most known threats.

So, Should We Stop Using Open-Source Models?

No! Open-source models are like buying groceries instead of always eating at a restaurant — cheaper, more flexible, and more customizable. But just like food safety, we need to take precautions:

Check the packaging — Scan models for known threats.

Avoid suspicious ingredients — Convert pickle files to SafeTensors.

Stir the pot — Fine-tune or compress models to disrupt simple hidden malware.

Stay informed — Keep up with the latest AI security research.

At the end of the day, open-source AI is incredibly powerful — but only if we cook with the right precautions.

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