对象检测是各种关键计算机视觉任务的基础,例如分割,对象跟踪和事件检测。要以令人满意的精度训练对象探测器,需要大量数据。但是,由于注释大型数据集涉及大量劳动力,这种数据策展任务通常被外包给第三方或依靠志愿者。这项工作揭示了此类数据策展管道的严重脆弱性。我们提出MACAB,即使数据策展人可以手动审核图像,也可以将干净的图像制作清洁的图像将后门浸入对象探测器中。我们观察到,当后门被不明确的天然物理触发器激活时,在野外实现了错误分类和披肩的后门效应。与带有清洁标签的现有图像分类任务相比,带有清洁通道的非分类对象检测具有挑战性,这是由于每个帧内有多个对象的复杂性,包括受害者和非视野性对象。通过建设性地滥用深度学习框架使用的图像尺度函数,II结合了所提出的对抗性清洁图像复制技术,以及在考虑到毒品数据选择标准的情况下,通过建设性地滥用图像尺度尺度,可以确保MACAB的功效。广泛的实验表明,在各种现实世界中,MacAB在90%的攻击成功率中表现出超过90%的攻击成功率。这包括披肩和错误分类后门效应,甚至限制了较小的攻击预算。最先进的检测技术无法有效地识别中毒样品。全面的视频演示位于https://youtu.be/ma7l_lpxkp4上,该演示基于yolov4倒置的毒药率为0.14%,yolov4 clokaking后门和更快的速度R-CNN错误分类后门。
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基于Web的网络钓鱼占数据泄露的90%以上,大多数Web浏览器和安全供应商都依靠机器学习(ML)模型作为缓解。尽管如此,还显示出在抗钓鱼聚合物(例如网络和Virustotal)上定期发布的链接可轻松绕过现有的探测器。先前的艺术表明,随着光突变的自动网站克隆正在吸引攻击者。这在当前文献中的暴露量有限,并导致基于ML的优势对策。这里的工作进行了第一项经验研究,该研究在广泛的循环中汇编和评估了各种最先进的克隆技术。我们收集了13,394个样品,发现了8,566个确认的网络钓鱼页面,使用7种不同的克隆机制针对4个流行网站。这些样品在受控平台中以防止意外访问的预防措施进行了删除的恶意代码复制。然后,我们将站点报告给Virustotal和其他平台,并定期对结果进行7天的调查,以确定每种克隆技术的功效。结果表明,没有安全供应商检测到我们的克隆,证明了对更有效的检测器的迫切需求。最后,我们提出了4项建议,以帮助网络开发人员和基于ML的防御能力减轻克隆攻击的风险。
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电子邮件网络钓鱼变得越来越普遍,随着时间的流逝,网络钓鱼变得更加复杂。为了打击这一上升,已经开发了许多用于检测网络钓鱼电子邮件的机器学习(ML)算法。但是,由于这些算法训练的电子邮件数据集有限,因此它们不擅长识别各种攻击,因此遭受了概念漂移的困扰。攻击者可以在其电子邮件或网站的统计特征上引入小小的变化,以成功绕过检测。随着时间的流逝,文献所报告的准确性与算法在现实世界中的实际有效性之间存在差距。这以频繁的假阳性和假阴性分类意识到自己。为此,我们建议对电子邮件进行多维风险评估,以减少攻击者调整电子邮件并避免检测的可行性。这种横向发送网络钓鱼检测配置文件的水平方法在其主要功能上发出了传入的电子邮件。我们开发了一个风险评估框架,其中包括三个模型,分析了电子邮件(1)威胁级别,(2)认知操纵和(3)电子邮件类型,我们合并了这些电子邮件类型以返回最终的风险评估评分。剖面人员不需要大量的数据集进行训练以有效,其对电子邮件功能的分析会减少概念漂移的影响。我们的参考器可以与ML方法结合使用,以减少其错误分类或作为培训阶段中大型电子邮件数据集的标签。我们在9000个合法的数据集中,使用最先进的ML算法评估了剖面人员对机器学习合奏的功效,并从一个大型澳大利亚大型研究组织的900个网络钓鱼电子邮件中进行了效力。我们的结果表明,探查者的概念漂移的影响减少了30%的假阳性,对ML合奏方法的虚假负面电子邮件分类少25%。
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Split学习(SL)通过允许客户在不共享原始数据的情况下协作培训深度学习模型来实现数据隐私保护。但是,SL仍然有限制,例如潜在的数据隐私泄漏和客户端的高计算。在这项研究中,我们建议将SL局部层进行二线以进行更快的计算(在移动设备上的培训和推理阶段的前进时间少17.5倍)和减少内存使用情况(最多减少32倍的内存和带宽要求) 。更重要的是,二进制的SL(B-SL)模型可以减少SL污染数据中的隐私泄漏,而模型精度的降解仅小。为了进一步增强隐私保护,我们还提出了两种新颖的方法:1)培训额外的局部泄漏损失,2)应用差异隐私,可以单独或同时集成到B-SL模型中。与多种基准模型相比,使用不同数据集的实验结果肯定了B-SL模型的优势。还说明了B-SL模型针对功能空间劫持攻击(FSHA)的有效性。我们的结果表明,B-SL模型对于具有高隐私保护要求(例如移动医疗保健应用程序)的轻巧的物联网/移动应用程序很有希望。
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后门深度学习(DL)模型的行为通常在清洁输入上,但在触发器输入时不端行为,因为后门攻击者希望为DL模型部署构成严重后果。最先进的防御是限于特定的后门攻击(源无关攻击)或在该机器学习(ML)专业知识或昂贵的计算资源中不适用于源友好的攻击。这项工作观察到所有现有的后门攻击都具有不可避免的内在弱点,不可转换性,即触发器输入劫持劫持模型,但不能对另一个尚未植入同一后门的模型有效。通过此密钥观察,我们提出了不可转换性的反向检测(NTD)来识别运行时在运行时的模型欠测试(MUT)的触发输入。特定,NTD允许潜在的回溯静电预测输入的类别。同时,NTD利用特征提取器(FE)来提取输入的特征向量,并且从其预测类随机拾取的一组样本,然后比较FE潜在空间中的输入和样本之间的相似性。如果相似性低,则输入是对逆势触发输入;否则,良性。 FE是一个免费的预训练模型,私下从开放平台保留。随着FE和MUT来自不同来源,攻击者非常不可能将相同的后门插入其中两者。由于不可转换性,不能将突变处工作的触发效果转移到FE,使NTD对不同类型的后门攻击有效。我们在三个流行的定制任务中评估NTD,如面部识别,交通标志识别和一般动物分类,结果确认NDT具有高效率(低假验收率)和具有低检测延迟的可用性(低误报率)。
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Spear Phishing is a harmful cyber-attack facing business and individuals worldwide. Considerable research has been conducted recently into the use of Machine Learning (ML) techniques to detect spear-phishing emails. ML-based solutions may suffer from zero-day attacks; unseen attacks unaccounted for in the training data. As new attacks emerge, classifiers trained on older data are unable to detect these new varieties of attacks resulting in increasingly inaccurate predictions. Spear Phishing detection also faces scalability challenges due to the growth of the required features which is proportional to the number of the senders within a receiver mailbox. This differs from traditional phishing attacks which typically perform only a binary classification between phishing and benign emails. Therefore, we devise a possible solution to these problems, named RAIDER: Reinforcement AIded Spear Phishing DEtectoR. A reinforcement-learning based feature evaluation system that can automatically find the optimum features for detecting different types of attacks. By leveraging a reward and penalty system, RAIDER allows for autonomous features selection. RAIDER also keeps the number of features to a minimum by selecting only the significant features to represent phishing emails and detect spear-phishing attacks. After extensive evaluation of RAIDER over 11,000 emails and across 3 attack scenarios, our results suggest that using reinforcement learning to automatically identify the significant features could reduce the dimensions of the required features by 55% in comparison to existing ML-based systems. It also improves the accuracy of detecting spoofing attacks by 4% from 90% to 94%. In addition, RAIDER demonstrates reasonable detection accuracy even against a sophisticated attack named Known Sender in which spear-phishing emails greatly resemble those of the impersonated sender.
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Existing integrity verification approaches for deep models are designed for private verification (i.e., assuming the service provider is honest, with white-box access to model parameters). However, private verification approaches do not allow model users to verify the model at run-time. Instead, they must trust the service provider, who may tamper with the verification results. In contrast, a public verification approach that considers the possibility of dishonest service providers can benefit a wider range of users. In this paper, we propose PublicCheck, a practical public integrity verification solution for services of run-time deep models. PublicCheck considers dishonest service providers, and overcomes public verification challenges of being lightweight, providing anti-counterfeiting protection, and having fingerprinting samples that appear smooth. To capture and fingerprint the inherent prediction behaviors of a run-time model, PublicCheck generates smoothly transformed and augmented encysted samples that are enclosed around the model's decision boundary while ensuring that the verification queries are indistinguishable from normal queries. PublicCheck is also applicable when knowledge of the target model is limited (e.g., with no knowledge of gradients or model parameters). A thorough evaluation of PublicCheck demonstrates the strong capability for model integrity breach detection (100% detection accuracy with less than 10 black-box API queries) against various model integrity attacks and model compression attacks. PublicCheck also demonstrates the smooth appearance, feasibility, and efficiency of generating a plethora of encysted samples for fingerprinting.
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