computer-use-agents-operating-real-os-indirect-injection-success-rates-measuredFor computer-use agents operating on a real OS, indirect-injection success rates measured with a fixed hand-written injection template understate vulnerability, because an attacker that adapts phrasing from the agent's own refusal trajectories can reach substantial success on models the fixed template never penetrates.
Ingested from a paper but not yet reviewed by a human. It is deliberately inert: it does not move any technique’s standing, does not count toward the backtest, and is excluded anywhere a claim would carry weight. Read the source before relying on it.
Capability: Following instructions hidden in data
Observed on
Black-box attacker controlling a forum comment the agent reads; 50 web-to-OS tasks from RedTeamCUA; three frontier CUAs (Claude Opus 4.6/4.8, Gemini 3.5 Flash); success requires bo.
Sources
- Measured on 50 sampled tasks per model, three models. Baseline is RedTeamCUA's single urgency-laden template: 16%/4%/0% versus 54%/24%/28% for the adaptive pipeline. An ablation separates compositional search from the feedback loop, and two principles discovered on Opus 4.6 raised success on the two unseen models. Small task sample; attacker and analyzer are one model (Grok-4.3), so results are not shown to be attacker-independent.
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Related claims
- For tool-using agents, enforcing injection defense as a deterministic provenance check on sensitive tool parameters — with the only model call reading the trusted user request and never fetched content — makes admission decisions invariant to how an injection is worded, whereas defenses that judge the agent's runtime plan or behavior with a model can be steered by reworded injections.Following instructions hidden in data · unreviewed
- Prompt injection defenses that report near-zero attack success on short-context benchmarks lose most of that protection when the injected instruction sits inside a document of thousands to tens of thousands of tokens: fine-tuned separation defenses and detect-localize-remove pipelines still let a large share of injections through on paper review, resume screening, code review and email threads.Following instructions hidden in data · unreviewed
- For tool-using agents, restricting capabilities at the harness level after untrusted content enters the context — revoking or tightening the parameter envelopes of skills that lie on graph paths to deployer-defined forbidden states — cuts indirect-injection attack success further than prompt-level or per-action authorization defenses, and does so with no extra model calls or tokens, because enforcement reads the transition graph rather than the natural-language content.Following instructions hidden in data · unreviewed
- When an LLM agent must reconcile user-supplied identity credentials against database records before a sensitive read or write, frontier and open models frequently skip the cross-field consistency check and act anyway, and the failure rate barely moves whether the request is simple or has several parallel sub-requests and whether the forged field is visually near-identical to the true one or completely unrelated.Checking claims against evidence · unreviewed
- A linear probe on a tool-calling model's hidden state at the last generated token detects incorrect tool-calls — including wrong-but-well-typed argument values that parsers and logs do not catch — and works better on larger models and at middle-to-late layers than at the final layer.Using the tools it is given · unreviewed
Notes
Drafted from the paper by a model and filed unreviewed. Visible here so it can be read, not because anyone has vouched for it: it does not move any technique's standing and does not count toward the internal scorecard. Drafted confidence: medium. Falsifier as drafted: An adaptive, feedback-driven injection search that fails to beat the fixed template on models where the template scores near zero, or whose gains vanish under the same deterministic joint-success oracle. Proposed technique, not catalogued: Failure-driven attack principle discovery.