Backdooring Open-Weight AI Models (www.schneier.com)

<p><a href="https://projectdiscovery.io/research/how-abliterated-models-can-get-you-pwned">This</a> is a problem:</p>
<blockquote><p>Any open model whose weights have been edited can carry a backdoor, whether it&#8217;s a task-specific fine-tune, a merged adapter or an abliterated build. We have abliterated models in the title because it&#8217;s the most popular reason people download modified weights without verifying what&#8217;s inside. Abliteration is a cheap fine-tune that takes away a model&#8217;s ability to refuse. You find the direction in the weights that carries &#8220;no&#8221; and subtract it. The model then answers things a safety-tuned version would turn down. It began as a research trick and it&#8217;s now routine before people upload a model to Hugging Face, where you&#8217;ll find abliterated builds of most of the popular open weights: Qwen, Llama, even OpenAI&#8217;s gpt-oss...</p></blockquote>