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2020-03-18
Yang, Yunxue, Ji, Guohua, Yang, Zhenqi, Xue, Shengjun.  2019.  Incentive Contract for Cybersecurity Information Sharing Considering Monitoring Signals. 2019 International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData). :507–512.
Cyber insurance is a viable method for cyber risk transfer. However, the cyber insurance faces critical challenges, the most important of which is lack of statistical data. In this paper, we proposed an incentive model considering monitoring signals for cybersecurity information haring based on the principal-agent theory. We studied the effect of monitoring signals on increasing the rationality of the incentive contract and reducing moral hazard in the process of cybersecurity information sharing, and analyzed factors influencing the effectiveness of the incentive contract. We show that by introducing monitoring signals, the insurer can collect more information about the effort level of the insured, and encourage the insured to share cybersecurity information based on the information sharing output and monitoring signals of the effort level, which can not only reduce the blindness of incentive to the insured in the process of cybersecurity information sharing, but also reduce moral hazard.
Li, Tao, Guo, Yuanbo, Ju, Ankang.  2019.  A Self-Attention-Based Approach for Named Entity Recognition in Cybersecurity. 2019 15th International Conference on Computational Intelligence and Security (CIS). :147–150.
With cybersecurity situation more and more complex, data-driven security has become indispensable. Numerous cybersecurity data exists in textual sources and data analysis is difficult for both security analyst and the machine. To convert the textual information into structured data for further automatic analysis, we extract cybersecurity-related entities and propose a self-attention-based neural network model for the named entity recognition in cybersecurity. Considering the single word feature not enough for identifying the entity, we introduce CNN to extract character feature which is then concatenated into the word feature. Then we add the self-attention mechanism based on the existing BiLSTM-CRF model. Finally, we evaluate the proposed model on the labelled dataset and obtain a better performance than the previous entity extraction model.
Offenberger, Spencer, Herman, Geoffrey L., Peterson, Peter, Sherman, Alan T, Golaszewski, Enis, Scheponik, Travis, Oliva, Linda.  2019.  Initial Validation of the Cybersecurity Concept Inventory: Pilot Testing and Expert Review. 2019 IEEE Frontiers in Education Conference (FIE). :1–9.
We analyze expert review and student performance data to evaluate the validity of the Cybersecurity Concept Inventory (CCI) for assessing student knowledge of core cybersecurity concepts after a first course on the topic. A panel of 12 experts in cybersecurity reviewed the CCI, and 142 students from six different institutions took the CCI as a pilot test. The panel reviewed each item of the CCI and the overwhelming majority rated every item as measuring appropriate cybersecurity knowledge. We administered the CCI to students taking a first cybersecurity course either online or proctored by the course instructor. We applied classical test theory to evaluate the quality of the CCI. This evaluation showed that the CCI is sufficiently reliable for measuring student knowledge of cybersecurity and that the CCI may be too difficult as a whole. We describe the results of the expert review and the pilot test and provide recommendations for the continued improvement of the CCI.
Wang, Johnson J. H..  2019.  Solving Cybersecurity Problem by Symmetric Dual-Space Formulation—Physical and Cybernetic. 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting. :601–602.
To address cybersecurity, this author proposed recently the approach of formulating it in symmetric dual-space and dual-system. This paper further explains this concept, beginning with symmetric Maxwell Equation (ME) and Fourier Transform (FT). The approach appears to be a powerful solution, with wide applications ranging from Electronic Warfare (EW) to 5G Mobile, etc.
Schwab, Stephen, Kline, Erik.  2019.  Cybersecurity Experimentation at Program Scale: Guidelines and Principles for Future Testbeds. 2019 IEEE European Symposium on Security and Privacy Workshops (EuroS PW). :94–102.
Cybersecurity Experimentation is often viewed narrowly in terms of a single technology or experiment. This paper reviews the experimentation life-cycle for two large scale research efforts that span multiple technologies. We identify salient aspects of each cybersecurity program, and capture guidelines based on eight years of experience. Extrapolating, we identify four principles for building future experimental infrastructure: 1) Reduce the cognitive burden on experimenters when designing and operating experiments. 2) Allow experimenters to encode their goals and constraints. 3) Provide flexibility in experimental design. 4) Provide multifaceted guidance to help experimenters produce high-quality experiments. By following these principles, future cybersecurity testbeds can enable significantly higher-quality experiments.
Kalashnikov, A.O., Anikina, E.V..  2019.  Complex Network Cybersecurity Monitoring Method. 2019 Twelfth International Conference "Management of large-scale system development" (MLSD). :1–3.
This paper considers one of the methods of efficient allocation of limited resources in special-purpose devices (sensors) to monitor complex network unit cybersecurity.
Zhang, Ruipeng, Xu, Chen, Xie, Mengjun.  2019.  Powering Hands-on Cybersecurity Practices with Cloud Computing. 2019 IEEE 27th International Conference on Network Protocols (ICNP). :1–2.
Cybersecurity education and training have gained increasing attention in all sectors due to the prevalence and quick evolution of cyberattacks. A variety of platforms and systems have been proposed and developed to accommodate the growing needs of hands-on cybersecurity practice. However, those systems are either lacking sufficient flexibility (e.g., tied to a specific virtual computing service provider, little customization support) or difficult to scale. In this work, we present a cloud-based platform named EZSetup for hands-on cybersecurity practice at scale and our experience of using it in class. EZSetup is customizable and cloud-agnostic. Users can create labs through an intuitive Web interface and deploy them onto one or multiple clouds. We have used NSF funded Chameleon cloud and our private OpenStack cloud to develop, test and deploy EZSetup. We have developed 14 network and security labs using the tool and included six labs in an undergraduate network security course in spring 2019. Our survey results show that students have very positive feedback on using EZSetup and computing clouds for hands-on cybersecurity practice.
Promyslov, Vitaly, Jharko, Elena, Semenkov, Kirill.  2019.  Principles of Physical and Information Model Integration for Cybersecurity Provision to a Nuclear Power Plant. 2019 Twelfth International Conference "Management of large-scale system development" (MLSD). :1–3.
For complex technical objects the research of cybersecurity problems should take into account both physical and information properties of the object. The paper considers a hybrid model that unifies information and physical models and may be used as a tool for countering cyber threats and for cybersecurity risk assessment at the design and operational stage of an object's lifecycle.
Williams, Laurie.  2019.  Science Leaves Clues. IEEE Security Privacy. 17:4–6.
The elusive science of security. Science advances when research results build upon prior findings through the evolution of hypotheses and theories about the fundamental relationships among variables within a context and considering the threats and limitations of the work. Some hypothesize that, through this science of security, the industry can take a more principled and systematic approach to securing systems, rather than reacting to the latest move by attackers. Others debate the utility of a science of security.
2020-02-05
Nathan Malkin, Serge Egelman, David Wagner.  2019.  Privacy Controls for Always-Listening Devices. New Security Paradigms Workshop (NSPW).

Intelligent voice assistants (IVAs) and other voice-enabled devices already form an integral component of the Internet of Things and will continue to grow in popularity. As their capabilities evolve, they will move beyond relying on the wake-words today’s IVAs use, engaging instead in continuous listening. Though potentially useful, the continuous recording and analysis of speech can pose a serious threat to individuals’ privacy. Ideally, users would be able to limit or control the types of information such devices have access to. But existing technical approaches are insufficient for enforcing any such restrictions. To begin formulating a solution, we develop a system- atic methodology for studying continuous-listening applications and survey architectural approaches to designing a system that enhances privacy while preserving the benefits of always-listening assistants.

2019-10-10
Alisa Frik, Leysan Nurgalieva, Julia Bernd, Joyce Lee, Florian Schaub, Serge Egelman.  2019.  Privacy and Security Threat Models and Mitigation Strategies of Older Adults. Fifteenth Symposium on Usable Privacy and Security (SOUPS 2019). :21–40.

Older adults (65+) are becoming primary users of emerging smart systems, especially in health care. However, these technologies are often not designed for older users and can pose serious privacy and security concerns due to their novelty, complexity, and propensity to collect and communicate vast amounts of sensitive information. Efforts to address such concerns must build on an in-depth understanding of older adults' perceptions and preferences about data privacy and security for these technologies, and accounting for variance in physical and cognitive abilities. In semi-structured interviews with 46 older adults, we identified a range of complex privacy and security attitudes and needs specific to this population, along with common threat models, misconceptions, and mitigation strategies. Our work adds depth to current models of how older adults' limited technical knowledge, experience, and age-related declines in ability amplify vulnerability to certain risks; we found that health, living situation, and finances play a notable role as well. We also found that older adults often experience usability issues or technical uncertainties in mitigating those risks -- and that managing privacy and security concerns frequently consists of limiting or avoiding technology use. We recommend educational approaches and usable technical protections that build on seniors' preferences.

2018-10-15
Benjamin E. Ujcich, University of Illinois at Urbana-Champaign, Samuel Jero, MIT Lincoln Laboratory, Anne Edmundson, Princeton University, Qi Wang, University of Illinois at Urbana-Champaign, Richard Skowyra, MIT Lincoln Laboratory, James Landry, MIT Lincoln Laboratory, Adam Bates, University of Illinois at Urbana-Champaign, William H. Sanders, University of Illinois at Urbana-Champaign, Cristina Nita-Rotaru, Northeastern University, Hamed Okhravi, MIT Lincoln Laboratroy.  2018.  Cross-App Poisoning in Software-Defined Networking. 2018 ACM Conference on Computer and Communications Security.

Software-defined networking (SDN) continues to grow in popularity because of its programmable and extensible control plane realized through network applications (apps). However, apps introduce significant security challenges that can systemically disrupt network operations, since apps must access or modify data in a shared control plane state. If our understanding of how such data propagate within the control plane is inadequate, apps can co-opt other apps, causing them to poison the control plane’s integrity. 

We present a class of SDN control plane integrity attacks that we call cross-app poisoning (CAP), in which an unprivileged app manipulates the shared control plane state to trick a privileged app into taking actions on its behalf. We demonstrate how role-based access control (RBAC) schemes are insufficient for preventing such attacks because they neither track information flow nor enforce information flow control (IFC). We also present a defense, ProvSDN, that uses data provenance to track information flow and serves as an online reference monitor to prevent CAP attacks. We implement ProvSDN on the ONOS SDN controller and demonstrate that information flow can be tracked with low-latency overheads.

2018-07-13
Yangfend Qu, Illinois Institute of Technology, Xin Liu, Illinois Institute of Technology, Dong Jin, Illinois Institute of Technology, Yuan Hong, Illinois Institute of Technology, Chen Chen, Argonne National Laboratory.  2018.  Enabling a Resilient and Self-healing PMU Infrastructure Using Centralized Network Control. 2018 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization.

Many of the emerging wide-area monitoring protection and control (WAMPAC) applications in modern electrical grids rely heavily on the availability and integrity of widespread phasor measurement unit (PMU) data. Therefore, it is critical to protect PMU networks against growing cyber-attacks and system faults. In this paper, we present a self-healing PMU network design that considers both power system observability and communication network characteristics. Our design utilizes centralized network control, such as the emerging software-defined networking (SDN) technology, to design resilient network self-healing algorithms against cyber-attacks. Upon detection of a cyber-attack, the PMU network can reconfigure itself to isolate compromised devices and re-route measurement
data with the goal of preserving the power system observability. We have developed a proof-of-concept system in a container-based network testbed using integer linear programming to solve a graphbased PMU system model.We also evaluate the system performance regarding the self-healing plan generation and installation using the IEEE 30-bus system.
 

2018-06-07
Uwagbole, S. O., Buchanan, W. J., Fan, L..  2017.  An applied pattern-driven corpus to predictive analytics in mitigating SQL injection attack. 2017 Seventh International Conference on Emerging Security Technologies (EST). :12–17.

Emerging computing relies heavily on secure backend storage for the massive size of big data originating from the Internet of Things (IoT) smart devices to the Cloud-hosted web applications. Structured Query Language (SQL) Injection Attack (SQLIA) remains an intruder's exploit of choice to pilfer confidential data from the back-end database with damaging ramifications. The existing approaches were all before the new emerging computing in the context of the Internet big data mining and as such will lack the ability to cope with new signatures concealed in a large volume of web requests over time. Also, these existing approaches were strings lookup approaches aimed at on-premise application domain boundary, not applicable to roaming Cloud-hosted services' edge Software-Defined Network (SDN) to application endpoints with large web request hits. Using a Machine Learning (ML) approach provides scalable big data mining for SQLIA detection and prevention. Unfortunately, the absence of corpus to train a classifier is an issue well known in SQLIA research in applying Artificial Intelligence (AI) techniques. This paper presents an application context pattern-driven corpus to train a supervised learning model. The model is trained with ML algorithms of Two-Class Support Vector Machine (TC SVM) and Two-Class Logistic Regression (TC LR) implemented on Microsoft Azure Machine Learning (MAML) studio to mitigate SQLIA. This scheme presented here, then forms the subject of the empirical evaluation in Receiver Operating Characteristic (ROC) curve.

Appelt, D., Panichella, A., Briand, L..  2017.  Automatically Repairing Web Application Firewalls Based on Successful SQL Injection Attacks. 2017 IEEE 28th International Symposium on Software Reliability Engineering (ISSRE). :339–350.

Testing and fixing Web Application Firewalls (WAFs) are two relevant and complementary challenges for security analysts. Automated testing helps to cost-effectively detect vulnerabilities in a WAF by generating effective test cases, i.e., attacks. Once vulnerabilities have been identified, the WAF needs to be fixed by augmenting its rule set to filter attacks without blocking legitimate requests. However, existing research suggests that rule sets are very difficult to understand and too complex to be manually fixed. In this paper, we formalise the problem of fixing vulnerable WAFs as a combinatorial optimisation problem. To solve it, we propose an automated approach that combines machine learning with multi-objective genetic algorithms. Given a set of legitimate requests and bypassing SQL injection attacks, our approach automatically infers regular expressions that, when added to the WAF's rule set, prevent many attacks while letting legitimate requests go through. Our empirical evaluation based on both open-source and proprietary WAFs shows that the generated filter rules are effective at blocking previously identified and successful SQL injection attacks (recall between 54.6% and 98.3%), while triggering in most cases no or few false positives (false positive rate between 0% and 2%).

Ghafarian, A..  2017.  A hybrid method for detection and prevention of SQL injection attacks. 2017 Computing Conference. :833–838.

SQL injection attack (SQLIA) pose a serious security threat to the database driven web applications. This kind of attack gives attackers easily access to the application's underlying database and to the potentially sensitive information these databases contain. A hacker through specifically designed input, can access content of the database that cannot otherwise be able to do so. This is usually done by altering SQL statements that are used within web applications. Due to importance of security of web applications, researchers have studied SQLIA detection and prevention extensively and have developed various methods. In this research, after reviewing the existing research in this field, we present a new hybrid method to reduce the vulnerability of the web applications. Our method is specifically designed to detect and prevent SQLIA. Our proposed method is consists of three phases namely, the database design, implementation, and at the common gateway interface (CGI). Details of our approach along with its pros and cons are discussed in detail.

Dikhit, A. S., Karodiya, K..  2017.  Result evaluation of field authentication based SQL injection and XSS attack exposure. 2017 International Conference on Information, Communication, Instrumentation and Control (ICICIC). :1–6.

Figuring innovations and development of web diminishes the exertion required for different procedures. Among them the most profited businesses are electronic frameworks, managing an account, showcasing, web based business and so on. This framework mostly includes the data trades ceaselessly starting with one host then onto the next. Amid this move there are such a variety of spots where the secrecy of the information and client gets loosed. Ordinarily the zone where there is greater likelihood of assault event is known as defenceless zones. Electronic framework association is one of such place where numerous clients performs there undertaking as indicated by the benefits allotted to them by the director. Here the aggressor makes the utilization of open ranges, for example, login or some different spots from where the noxious script is embedded into the framework. This scripts points towards trading off the security imperatives intended for the framework. Few of them identified with clients embedded scripts towards web communications are SQL infusion and cross webpage scripting (XSS). Such assaults must be distinguished and evacuated before they have an effect on the security and classification of the information. Amid the most recent couple of years different arrangements have been incorporated to the framework for making such security issues settled on time. Input approvals is one of the notable fields however experiences the issue of execution drops and constrained coordinating. Some other component, for example, disinfection and polluting will create high false report demonstrating the misclassified designs. At the center, both include string assessment and change investigation towards un-trusted hotspots for totally deciphering the effect and profundity of the assault. This work proposes an enhanced lead based assault discovery with specifically message fields for viably identifying the malevolent scripts. The work obstructs the ordinary access for malignant so- rce utilizing and hearty manage coordinating through unified vault which routinely gets refreshed. At the underlying level of assessment, the work appears to give a solid base to further research.

Appiah, B., Opoku-Mensah, E., Qin, Z..  2017.  SQL injection attack detection using fingerprints and pattern matching technique. 2017 8th IEEE International Conference on Software Engineering and Service Science (ICSESS). :583–587.

Web-Based applications are becoming more increasingly technically complex and sophisticated. The very nature of their feature-rich design and their capability to collate, process, and disseminate information over the Internet or from within an intranet makes them a popular target for attack. According to Open Web Application Security Project (OWASP) Top Ten Cheat sheet-2017, SQL Injection Attack is at peak among online attacks. This can be attributed primarily to lack of awareness on software security. Developing effective SQL injection detection approaches has been a challenge in spite of extensive research in this area. In this paper, we propose a signature based SQL injection attack detection framework by integrating fingerprinting method and Pattern Matching to distinguish genuine SQL queries from malicious queries. Our framework monitors SQL queries to the database and compares them against a dataset of signatures from known SQL injection attacks. If the fingerprint method cannot determine the legitimacy of query alone, then the Aho Corasick algorithm is invoked to ascertain whether attack signatures appear in the queries. The initial experimental results of our framework indicate the approach can identify wide variety of SQL injection attacks with negligible impact on performance.

Lodeiro-Santiago, Moisés, Caballero-Gil, Cándido, Caballero-Gil, Pino.  2017.  Collaborative SQL-injections Detection System with Machine Learning. Proceedings of the 1st International Conference on Internet of Things and Machine Learning. :45:1–45:5.
Data mining and information extraction from data is a field that has gained relevance in recent years thanks to techniques based on artificial intelligence and use of machine and deep learning. The main aim of the present work is the development of a tool based on a previous behaviour study of security audit tools (oriented to SQL pentesting) with the purpose of creating testing sets capable of performing an accurate detection of a SQL attack. The study is based on the information collected through the generated web server logs in a pentesting laboratory environment. Then, making use of the common extracted patterns from the logs, each attack vector has been classified in risk levels (dangerous attack, normal attack, non-attack, etc.). Finally, a training with the generated data was performed in order to obtain a classifier system that has a variable performance between 97 and 99 percent in positive attack detection. The training data is shared to other servers in order to create a distributed network capable of deciding if a query is an attack or is a real petition and inform to connected clients in order to block the petitions from the attacker's IP.
Liang, Jingxi, Zhao, Wen, Ye, Wei.  2017.  Anomaly-Based Web Attack Detection: A Deep Learning Approach. Proceedings of the 2017 VI International Conference on Network, Communication and Computing. :80–85.
As the era of cloud technology arises, more and more people are beginning to migrate their applications and personal data to the cloud. This makes web-based applications an attractive target for cyber-attacks. As a result, web-based applications now need more protections than ever. However, current anomaly-based web attack detection approaches face the difficulties like unsatisfying accuracy and lack of generalization. And the rule-based web attack detection can hardly fight unknown attacks and is relatively easy to bypass. Therefore, we propose a novel deep learning approach to detect anomalous requests. Our approach is to first train two Recurrent Neural Networks (RNNs) with the complicated recurrent unit (LSTM unit or GRU unit) to learn the normal request patterns using only normal requests unsupervisedly and then supervisedly train a neural network classifier which takes the output of RNNs as the input to discriminate between anomalous and normal requests. We tested our model on two datasets and the results showed that our model was competitive with the state-of-the-art. Our approach frees us from feature selection. Also to the best of our knowledge, this is the first time that the RNN is applied on anomaly-based web attack detection systems.
Yuan, Shuhan, Wu, Xintao, Li, Jun, Lu, Aidong.  2017.  Spectrum-based Deep Neural Networks for Fraud Detection. Proceedings of the 2017 ACM on Conference on Information and Knowledge Management. :2419–2422.
In this paper, we focus on fraud detection on a signed graph with only a small set of labeled training data. We propose a novel framework that combines deep neural networks and spectral graph analysis. In particular, we use the node projection (called as spectral coordinate) in the low dimensional spectral space of the graph's adjacency matrix as the input of deep neural networks. Spectral coordinates in the spectral space capture the most useful topology information of the network. Due to the small dimension of spectral coordinates (compared with the dimension of the adjacency matrix derived from a graph), training deep neural networks becomes feasible. We develop and evaluate two neural networks, deep autoencoder and convolutional neural network, in our fraud detection framework. Experimental results on a real signed graph show that our spectrum based deep neural networks are effective in fraud detection.
Xu, Xiaojun, Liu, Chang, Feng, Qian, Yin, Heng, Song, Le, Song, Dawn.  2017.  Neural Network-based Graph Embedding for Cross-Platform Binary Code Similarity Detection. Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security. :363–376.

The problem of cross-platform binary code similarity detection aims at detecting whether two binary functions coming from different platforms are similar or not. It has many security applications, including plagiarism detection, malware detection, vulnerability search, etc. Existing approaches rely on approximate graph-matching algorithms, which are inevitably slow and sometimes inaccurate, and hard to adapt to a new task. To address these issues, in this work, we propose a novel neural network-based approach to compute the embedding, i.e., a numeric vector, based on the control flow graph of each binary function, then the similarity detection can be done efficiently by measuring the distance between the embeddings for two functions. We implement a prototype called Gemini. Our extensive evaluation shows that Gemini outperforms the state-of-the-art approaches by large margins with respect to similarity detection accuracy. Further, Gemini can speed up prior art's embedding generation time by 3 to 4 orders of magnitude and reduce the required training time from more than 1 week down to 30 minutes to 10 hours. Our real world case studies demonstrate that Gemini can identify significantly more vulnerable firmware images than the state-of-the-art, i.e., Genius. Our research showcases a successful application of deep learning on computer security problems.

Lahrouni, Youssef, Pereira, Caroly, Bensaber, Boucif Amar, Biskri, Ismaïl.  2017.  Using Mathematical Methods Against Denial of Service (DoS) Attacks in VANET. Proceedings of the 15th ACM International Symposium on Mobility Management and Wireless Access. :17–22.

VANET network is a new technology on which future intelligent transport systems are based; its purpose is to develop the vehicular environment and make it more comfortable. In addition, it provides more safety for drivers and cars on the road. Therefore, we have to make this technology as secured as possible against many threats. As VANET is a subclass of MANET, it has inherited many security problems but with a different architecture and DOS attacks are one of them. In this paper, we have focused on DOS attacks that prevent users to receive the right information at the right moment. We have analyzed DOS attacks behavior and effects on the network using different mathematical models in order to find an efficient solution.

Yakura, Hiromu, Shinozaki, Shinnosuke, Nishimura, Reon, Oyama, Yoshihiro, Sakuma, Jun.  2017.  Malware Analysis of Imaged Binary Samples by Convolutional Neural Network with Attention Mechanism. Proceedings of the 10th ACM Workshop on Artificial Intelligence and Security. :55–56.

This paper presents a method to extract important byte sequences in malware samples by application of convolutional neural network (CNN) to images converted from binary data. This method, by combining a technique called the attention mechanism into CNN, enables calculation of an "attention map," which shows regions having higher importance for classification in the image. The extracted region with higher importance can provide useful information for human analysts who investigate the functionalities of unknown malware samples. Results of our evaluation experiment using malware dataset show that the proposed method provides higher classification accuracy than a conventional method. Furthermore, analysis of malware samples based on the calculated attention map confirmed that the extracted sequences provide useful information for manual analysis.

Chen, Pin-Yu, Zhang, Huan, Sharma, Yash, Yi, Jinfeng, Hsieh, Cho-Jui.  2017.  ZOO: Zeroth Order Optimization Based Black-box Attacks to Deep Neural Networks Without Training Substitute Models. Proceedings of the 10th ACM Workshop on Artificial Intelligence and Security. :15–26.
Deep neural networks (DNNs) are one of the most prominent technologies of our time, as they achieve state-of-the-art performance in many machine learning tasks, including but not limited to image classification, text mining, and speech processing. However, recent research on DNNs has indicated ever-increasing concern on the robustness to adversarial examples, especially for security-critical tasks such as traffic sign identification for autonomous driving. Studies have unveiled the vulnerability of a well-trained DNN by demonstrating the ability of generating barely noticeable (to both human and machines) adversarial images that lead to misclassification. Furthermore, researchers have shown that these adversarial images are highly transferable by simply training and attacking a substitute model built upon the target model, known as a black-box attack to DNNs. Similar to the setting of training substitute models, in this paper we propose an effective black-box attack that also only has access to the input (images) and the output (confidence scores) of a targeted DNN. However, different from leveraging attack transferability from substitute models, we propose zeroth order optimization (ZOO) based attacks to directly estimate the gradients of the targeted DNN for generating adversarial examples. We use zeroth order stochastic coordinate descent along with dimension reduction, hierarchical attack and importance sampling techniques to efficiently attack black-box models. By exploiting zeroth order optimization, improved attacks to the targeted DNN can be accomplished, sparing the need for training substitute models and avoiding the loss in attack transferability. Experimental results on MNIST, CIFAR10 and ImageNet show that the proposed ZOO attack is as effective as the state-of-the-art white-box attack (e.g., Carlini and Wagner's attack) and significantly outperforms existing black-box attacks via substitute models.