# Security Assessment of DeepSeek Harness with A.I.G: Evaluating Resistance to Indirect Prompt Injection

arXiv: https://arxiv.org/abs/2608.16393 · HTML: https://mlsanity.com/paper/2608.16393/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- Placed in Prompt injection and agent security, one of 12 directions in LLM safety and security.
- Builds on 9 of its 11 references that are in the map.
- First posted on arXiv 17 Aug 2026.

## Placed in

- LLM safety and security / [Prompt injection and agent security](https://mlsanity.com/safety/prompt-injection-and-agent-security/)

## Builds on (most cited first, 9 of 9)

- [Not what you've signed up for: Compromising Real-World LLM-Integrated Applications with Indirect Prompt Injection](https://mlsanity.com/paper/2302.12173/) (2023)
- [InjecAgent: Benchmarking Indirect Prompt Injections in Tool-Integrated Large Language Model Agents](https://mlsanity.com/paper/2403.02691/) (2024)
- [AgentPoison: Red-teaming LLM Agents via Poisoning Memory or Knowledge Bases](https://mlsanity.com/paper/2407.12784/) (2024)
- [StruQ: Defending Against Prompt Injection with Structured Queries](https://mlsanity.com/paper/2402.06363/) (2024)
- [Defending Against Indirect Prompt Injection Attacks With Spotlighting](https://mlsanity.com/paper/2403.14720/) (2024)
- [Benchmarking and Defending Against Indirect Prompt Injection Attacks on Large Language Models](https://mlsanity.com/paper/2312.14197/) (2023)
- [AgentVisor: Defending LLM Agents Against Prompt Injection via Semantic Virtualization](https://mlsanity.com/paper/2604.24118/) (2026)
- [SkillJack: Persistent Skill Backdoors in Self-Evolving Agents](https://mlsanity.com/paper/2608.03509/) (2026)
- [Securing the AI Agent: A Unified Framework for Multi-Layer Agent Red Teaming](https://mlsanity.com/paper/2606.31227/) (2026)

## Built on by (most cited first, 1 of 1)

- [Towards In-Parameter Memory Augmentation for Large Language Models](https://mlsanity.com/paper/2610.08630/) (2026)

## Abstract (arXiv)

We assess indirect prompt injection in DeepSeek Harness (DSH), using AI-Infra-Guard (A.I.G) to construct tests, deliver controlled taint, execute DSH, collect traces, and judge outcomes. The study covers 14,560 controlled executions over 16 indirect-content channels, text and file carrier modes, 35 payload objectives, one unmodified baseline, and 12 attack methods. The experiment preserves DSH's agent loop, tool registry, model adapter, and session-event path; source tools and sensitive sinks are local fixtures, so attempted actions are recorded without external side effects. We evaluate each trace with a deterministic rule-based judge, JudgeR (RuleJudge), and a semantic LLM-based judge, JudgeL (LLMJudge). The strongest observed attack success rates are 17.0% under JudgeL for fake-completion attack in text mode, 25.5% under JudgeR for hidden Unicode in file mode, and 16.0% under JudgeR for the skills channel in file mode. JudgeL also assigns partial compliance more often than JudgeR (7.3% versus 2.0%). We relate these results to DSH's treatment of tool results, additional contexts, and tool-call policy hooks, then identify controls that should sit between untrusted content and sensitive actions. Our code is available at https://github.com/Tencent/AI-Infra-Guard/tree/main/Research/deepseek-harness-security-assessment .
