IoT repackaging refers to an attack devoted to tampering with a legitimate firmware package by modifying its content (e.g., injecting some malicious code) and re-distributing it in the wild. In such a scenario, the firmware delivery and update processes play a central role in ensuring firmware integrity. Unfortunately, several existing solutions lack proper integrity verification, exposing firmware to repackaging attacks. If this is not the case, they still require an external trust anchor (e.g., signing keys or secure storage technologies), which could limit their adoption in resource-constrained environments. In addition, state-of-the-art frameworks do not cope with the entire firmware production and delivery process, thereby failing to protect the content generated by the firmware producers through the whole supply chain. To mitigate such a problem, in this paper, we introduce PARIOT, a novel self-protecting scheme for IoT that allows the injection of integrity checks, called anti-tampering (AT) controls, directly into the firmware. The AT controls enable the runtime detection of repackaging attempts without needing external trust anchors or computationally expensive systems. PARIOT can be adopted on top of existing state-of-the-art solutions ensuring the widest compatibility with current IoT ecosystems and update frameworks. Also, we have implemented this scheme into PARIOTIC, a prototype to automatically protect C/C++ IoT firmware. The evaluation phase of 50 real-world firmware samples demonstrated the feasibility of the proposed methodology and its robustness against practical repackaging attacks without altering the firmware behavior or severe overheads.

翻译：物联网重打包是指一种攻击行为，旨在通过修改合法固件包的内容（如注入恶意代码）并重新分发至现实环境中。在此类场景下，固件的交付与更新流程对于保障固件完整性起着核心作用。然而，现有多种解决方案缺乏适当的完整性验证机制，导致固件暴露于重打包攻击风险之中。即便具备此类验证，这些方案仍需要外部信任锚点（如签名密钥或安全存储技术），这在资源受限环境中可能限制其应用推广。此外，现有主流框架未能覆盖固件生产与交付的全流程，因而无法保护固件生产者在整个供应链中生成的内容。为解决该问题，本文提出PARIOT——一种面向物联网的新型自保护方案，该方案允许将完整性检查（称为防篡改控制，AT控制）直接注入固件之中。AT控制能够在无需外部信任锚点或高计算开销系统的情况下，实现重打包攻击的运行时检测。PARIOT可基于现有主流解决方案部署，确保与当前物联网生态系统及更新框架的最大兼容性。同时，我们已将本方案实现为PARIOTIC原型系统，用于自动保护C/C++物联网固件。通过对50个真实固件样本的评估，验证了所提方法的可行性及其对实际重打包攻击的鲁棒性，且不会改变固件行为或引入显著开销。