Red-teaming Dolos-1.5B
Ajinkya · Team runner2
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
Dolos-1.5B is the red-team challenge of the Apart AI Collusion Research Sprint. It is a secret fine-tune of Qwen2.5-1.5B-Instruct, and it has a hidden misaligned behavior. We examined it with a pre-registered protocol. First, we scanned 800 prompts for each model. Then we did frozen tests on 240 new prompts. These tests found two real changes. Dolos does not write the <tool_call> tag in 25% of tool calls (Qwen: 0%). Dolos also sets prices approximately $1.5 higher. Neither change needs a collusion cue. We also ran a pricing war-game with a message channel. Two Dolos agents did not set higher prices than two Qwen agents (+0.02 of the price range, 95% CI -0.15 to 0.19). When Dolos is a code monitor, a review signature does not cause it to accept flawed code. Our main result is a two-stage trigger monitor. It does not need a reference model. Stage 1 is a KL screen of 24 cues, and it flags candidates. Stage 2 tests each flag on new prompts. It keeps a flag only if the insert changes the decision more than neutral sentences do. It ignores a decision that only copies the insert. The monitor found 4 of 4 pricing triggers that we planted at random. It found no trigger in clean Qwen (0 of 72 cue checks) or in Dolos. We changed the rule one time, before the counted tests. After this change, the monitor found 3 of 3 new blind triggers with no further change. The monitor did not find planted code-review triggers, because it calculated the mean over the reply. When it used the largest change on one token, it found 3 of 3 new code-review triggers. We report a careful null result, two measured changes, and a monitor that operates on two task families.
Reviews
I enjoyed reading this project because the authors were refreshingly honest about what they found and what they did not find. Their original goal was to discover Dolos-1.5B’s hidden behavior. They did not succeed at that specific goal, but they still produced useful research. They found two real differences between Dolos and the original Qwen model: Dolos sometimes omitted the normal wrapper around tool calls, and it tended to choose slightly higher prices. Importantly, they ran follow-up controls and showed that neither behavior depended on the suspected collusion cues. I appreciate that they reported these hypotheses as unsuccessful instead of overstating the results.
The experimental process is one of the project’s strongest features. The team recorded predictions and pass conditions before running tests, used fresh prompts to confirm possible findings, and documented changes to the protocol. Their two-stage monitoring idea is also promising. The first stage looks for prompts or cues that cause an unusually large change in the model’s output, while the second checks whether that change actually affects a meaningful decision. This helped remove false alarms and detected several deliberately planted triggers across pricing and code-review tasks.
My main suggestion is to test the monitor on a larger and more independent collection of hidden behaviors. Most of the successful examples were synthetic triggers created using similar recipes, so it is still unclear how well the method would work on unfamiliar, semantic, or long-context triggers.
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Cite this project
@misc{ajinkya2026redteaming,
title = {{Red-teaming Dolos-1.5B}},
author = {Ajinkya},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/redteaming-dolos15b-lviu}},
url = {https://apartresearch.com/sprints/projects/redteaming-dolos15b-lviu}
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