New AI-Security Model: Wolf Defender

3 min

Over the last weeks, we tried to further improve our model and reduce FPR.

We achieved amazing results by improving the data instead of the model.

I. Data > Model

Instead of chasing new architectures, we focused on:


  • dataset cleaning

  • removing mislabeled samples

  • improving data balance

  • adding realistic edge cases


This alone pushed our model from ~0.90 → 0.95 F1.

II. Reducing False Positives (the real problem)

Most prompt injection detectors fail in production because of false positives.

We made this our primary optimization target.

Example (Qualifire benchmark):

→ FPR reduced from ~0.11 → ~0.03

And importantly:

This was not achieved by training on benchmark data.

Instead, we introduced:


  • hard benign examples

  • injection-looking but safe prompts

  • real-world developer text (docs, issues, discussions)


This forces the model to actually learn the difference between:


  • malicious structure

  • and harmless context


The Result


  • Top-tier performance across benchmarks

  • Lowest FPR across benchmarks

  • Strong generalization across datasets


On average, we now outperform:


  • existing open-weight detectors

  • and even fine-tuned LLM-based solutions (e.g. Sentinel)


Small Model, Big Impact

We also trained a 50% smaller variant:

→ minimal performance drop → strong benchmark results

This is critical because it enables: aggressive quantization -> efficient deployment

What’s next

Our next step:

→ Reduce model size from ~500MB → <250MB → while maintaining state-of-the-art performance

This is how real AI security should work:


  • on-device

  • real-time

  • no cloud dependency

  • no data leaving the system


Model

https://huggingface.co/patronus-studio/wolf-defender-prompt-injection

We believe the future of AI security is:

local, fast, and data-driven.

Patronus Protect - on-device AI Security

© 2026 Casdo Labs GmbH · All rights reserved.

Legal

Patronus Protect - on-device AI Security

© 2026 Casdo Labs GmbH · All rights reserved.

Legal

Patronus Protect - on-device AI Security

© 2026 Casdo Labs GmbH · All rights reserved.

Legal