论文标题
无需了解物理:基于过程的无模型异常检测对工业控制系统的弹性
No Need to Know Physics: Resilience of Process-based Model-free Anomaly Detection for Industrial Control Systems
论文作者
论文摘要
近年来,提出了许多针对工业控制系统的基于过程的异常检测方案。在这项工作中,我们提供了对此类方案的第一个系统分析,并介绍了这些检测系统验证的属性分类法。然后,我们提出了一个新颖的通用框架,以生成违反系统物理特性的对抗性欺骗信号,并使用该框架分析在顶级安全会议上发布的四个异常检测器。我们发现,其中三个检测器容易受到许多对抗操作(例如,欺骗预先计算的模式),我们称它们称为合成传感器欺骗,而一种是反对我们的攻击的弹性。我们研究了其弹性的根源,并证明它来自我们引入的属性。我们的攻击降低了攻击方案的召回(真正的正率),使它们无法正确检测异常。因此,我们在异常检测器中发现的脆弱性表明(尽管有原始的良好检测性能),这些检测器仍无法可靠地学习系统的物理特性。即使是预期(基于经过验证的属性)的弹性也有弹性。我们认为,我们的发现表明了对数据集中更完整的攻击的必要性,以及对基于过程的异常检测器的更批判性分析。我们计划将我们的实施释放为开源,以及两个公共数据集的扩展,并与我们的框架生成的一组合成传感器欺骗攻击。
In recent years, a number of process-based anomaly detection schemes for Industrial Control Systems were proposed. In this work, we provide the first systematic analysis of such schemes, and introduce a taxonomy of properties that are verified by those detection systems. We then present a novel general framework to generate adversarial spoofing signals that violate physical properties of the system, and use the framework to analyze four anomaly detectors published at top security conferences. We find that three of those detectors are susceptible to a number of adversarial manipulations (e.g., spoofing with precomputed patterns), which we call Synthetic Sensor Spoofing and one is resilient against our attacks. We investigate the root of its resilience and demonstrate that it comes from the properties that we introduced. Our attacks reduce the Recall (True Positive Rate) of the attacked schemes making them not able to correctly detect anomalies. Thus, the vulnerabilities we discovered in the anomaly detectors show that (despite an original good detection performance), those detectors are not able to reliably learn physical properties of the system. Even attacks that prior work was expected to be resilient against (based on verified properties) were found to be successful. We argue that our findings demonstrate the need for both more complete attacks in datasets, and more critical analysis of process-based anomaly detectors. We plan to release our implementation as open-source, together with an extension of two public datasets with a set of Synthetic Sensor Spoofing attacks as generated by our framework.