Baojun Liu (刘保君)

Baojun Liu (刘保君)

Assistant Professor

Baojun Liu (刘保君)

Assistant Professor
FIT 4-204, Tsinghua University, Beijing, China 100084
(+86) 130~5153~7959
lbj [at] tsinghua -dot- edu -dot- cn

Headline

Main research areas: network infrastructure security, internet measurement and security analytics, cybercrime detection.
Recruits approximately 2-3 PhD/Master students each year. Note: Those interested must contact me by email in advance and go through a probationary period.
Welcome students who are interested in network security, curious about technology, self-driven, and excel in programming and English to contact me.
Openings for postdoctoral researchers, research assistants, engineers, visiting students, visiting scholars, and interns. Please send me your resume if interested.

About

Assistant Professor (PhD supervisor) at the Network Security Lab (NISL), Institute for Network Sciences and Cyberspace, Tsinghua University.
In 2023, selected for Top Young Scholar of National “Ten Thousand Talent Program”.
In 2020, selected for Tsinghua University’s “Shuimu Scholar Program”.
In 2022, received the ACM China Computer Security Association “Rising Star Award”.
As project leader, has hosted the Key Program of National Defense Pre-Research Foundation of China, National Natural Science Foundation of China projects, Alibaba Innovative Research Program projects, CCF-Tencent RhinoBird Foundation projects, and joint research projects between Tsinghua University and China Telecom.

Research Interests

  • Internet Network Measurement
  • Domain Name System Security
  • TLS/HTTPS Security
  • Cybercrime and Underground Economy

Education

  • Ph.D. in Computer Science, Tsinghua University, China. 2015-2020. Advisor: Prof. Ying Liu and Prof. Haixin Duan, Dissertation: Research on Security of Internet Domain Name System.
  • Visiting Scholar, International Computer Science Institute, University of California, Berkeley, USA, 2018-2019.
  • B.S. in Electronic Engineering, XiDian University, China. 2011-2015.

Professional Experience

  • Assistant Professor, Tsinghua University, China, 2022 - present.
  • Postdoc Researcher, Tsinghua University, China, 2020 - 2022.

Conference Papers

  • Xiang Li, Wei Xu, Baojun Liu, Mingming Zhang, Zhou Li, Jia Zhang, Deliang Chang, Xiaofeng Zheng, Chuhan Wang, Jianjun Chen, Haixin Duan and Qi Li. TuDoor Attack: Systematically Exploring and Exploiting Logic Vulnerabilities in DNS Response Pre-processing with Malformed Packets, Proceedings of The 45th IEEE Symposium on Security and Privacy (IEEE S&P), San Francisco, California, May 20–23, 2024.

  • Fenglu Zhang, Yunyi Zhang, Baojun Liu, Eihal Alowaisheq, Lingyun Ying, Xiang Li, Zaifeng Zhang, Ying Liu, Haixin Duan and Min Zhang. Wolf in Sheep’s Clothing: Evaluating the Security Risks of the Undelegated Record on DNS Hosting Services, Proceedings of The 2023 Internet Measurement Conference (IMC), Montréal, Canada, October 24 - 26, 2023.

  • Fenglu Zhang, Baojun Liu, Eihal Alowaisheq, Jianjun Chen, Chaoyi Lu, Linjian Song, Yong Ma, Ying Liu, Haixin Duan and Min Yang. Silence is not Golden: Disrupting the Load Balancing of Authoritative DNS Servers, Proceedings of The 30th ACM Conference on Computer and Communications Security (CCS), Copenhagen, Denmark, November 26-30, 2023.

  • Wei Xu, Xiang Li, Chaoyi Lu, Baojun Liu, Jia Zhang, Jianjun Chen, Tao Wan and Haixin Duan. TsuKing: Coordinating DNS Resolvers and Queries into Potent DoS Amplifiers, Proceedings of The 30th ACM Conference on Computer and Communications Security (CCS), Copenhagen, Denmark, November 26-30, 2023.

  • Zhenrui Zhang, Geng Hong, Xiang Li, Zhuoqun Fu, Jia Zhang, Mingxuan Liu, Chuhan Wang, Jianjun Chen, Baojun Liu, Haixin Duan, Chao Zhang and Min Yang. Under the Dark: A Systematical Study of Stealthy Mining Pools (Ab)use in the Wild, Proceedings of The 30th ACM Conference on Computer and Communications Security (CCS), Copenhagen, Denmark, November 26-30, 2023.

  • Xiang Li, Chaoyi Lu, Baojun Liu, Qifan Zhang, Zhou Li, Haixin Duan and Qi Li. The Maginot Line: Attacking the Boundary of DNS Caching Protection, Proceedings of The 32nd USENIX Security Symposium (USENIX Security), Anaheim, California, USA, August 9-11, 2023.

  • Run Guo, Jianjun Chen, Yihang Wang, Keran Mu, Baojun Liu, Xiang Li, Chao Zhang, Haixin Duan and Jianping Wu. Temporal CDN-Convex Lens: A CDN-Assisted Practical Pulsing DDoS Attack, Proceedings of The 32nd USENIX Security Symposium (USENIX Security), Anaheim, California, USA, August 9-11, 2023.

  • Mingming Zhang, Xiang Li, Baojun Liu, Jianju Lu, Yiming Zhang, Jianjun Chen, Haixin Duan, Shuang Hao and Xiaofeng Zheng. Detecting and Measuring Security Risks of Hosting-Based Dangling Domains, Proceedings of The 2023 ACM SIGMETRICS (ACM SIGMETRICS), Orlando, Florida, USA, June 19-23, 2023.

  • Xiang Li, Baojun Liu, Xuesong Bai, Mingming Zhang, Qifan Zhang, Zhou Li, Haixin Duan and Qi Li. Ghost Domain Reloaded: Vulnerable Links in the Domain Name Delegation and Revocation, Proceedings of The 30th Annual Network and Distributed Security Symposium (NDSS), San Diego, California, USA, 27 February – 3 March, 2023.

  • Mingxuan Liu, Yiming Zhang, Baojun Liu and Haixin Duan. Exploring the Characteristics and Security Risks of Emerging Emoji Domain Names, Proceedings of The 27th European Symposium on Research in Computer Security (ESORICS), Copenhagen, Denmark, September 26-30, 2022.

  • Huikai Xu, Miao Yu, Yanhao Wang, Yue Liu, Qinsheng Hou, Zhenbang Ma, Haixin Duan, Jianwei Zhuge and Baojun Liu. Trampoline Over the Air: Breaking in IoT Devices Through MQTT Brokers, Proceedings of The 7th IEEE European Symposium on Security and Privacy (EuroS&P), Genoa, June 6-10, 2022.

  • Fenglu Zhang, Chaoyi Lu, Baojun Liu, Haixin Duan and Ying Liu. Measuring the Practical Effect of DNS Root Server Instances: A China-Wide Case Study, Proceedings of Passive and Active Measurement Conference (PAM), Virtual event, March 28-30, 2022.

  • Qinge Xie, Shujun Tang, Xiaofeng Zheng, Qingran Lin, Baojun Liu, Haixin Duan and Frank Li. Building an Open, Robust, and Stable Voting-Based Internet Domain Top List, Proceedings of The 31th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 10-12, 2022.

  • Chuhan Wang, Kaiwen Shen, Minglei Guo, Yuxuan Zhao, Mingming Zhang, Jianjun Chen, Baojun Liu, Xiaofeng Zheng, Haixin Duan, Yanzhong Lin and Qingfeng Pan. A Large-scale and Longitudinal Measurement Study of DKIM Deployment, Proceedings of The 31th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 10-12, 2022.

  • Xuewei Feng, Qi Li, Kun Sun, Ke Xu, Baojun Liu, Xiaofeng Zheng, Qiushi Yang, Haixin Duan and Zhiyun Qian. PMTUD is not Panacea: Revisiting IP Fragmentation Attacks against TCP, Proceedings of The 29th Annual Network and Distributed Security Symposium (NDSS), San Diego, California, 27 Feruary - 3 March, 2022.

  • Mingxuan Liu, Yiming Zhang, Baojun Liu, Zhou Li, Haixin Duan and Donghong Sun. Detecting and Characterizing SMS Spearphising Attacks, Proceedings of The 37th Annual Computer Security Applications Conference (ACSAC), Austin, Texas, USA, December 6-10, 2021.

  • Yiming Zhang, Baojun Liu, Chaoyi Lu, Zhou Li, Haixin Duan, Jiachen Li and Zaifeng Zhang. Rusted Anchors: A National Client-Side View of Hidden Root CAs in the Web PKI Ecosystem, Proceedings of The 28th ACM Conference on Computer and Communications Security (CCS), Seoul, South Korea, November 15-19, 2021.

  • Xiang Li, Baojun Liu, Xiaofeng Zheng, Haixin Duan, Qi Li and Youjun Huang. Fast IPv6 Network Periphery Discovery and Security Implications, Proceedings of The 51th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Virtual, June 21-24, 2021.

  • Chaoyi Lu, Baojun Liu, Yiming Zhang, Zhou Li, Fenglu Zhang, Haixin Duan, Ying Liu, Joann Chen, Jinjin Liang, Zaifeng Zhang, Shuang Hao and Min Yang. From WHOIS to WHOWAS: A Large-Scale Measurement Study of Domain Registration Privacy under the GDPR, Proceedings of The 28th Annual Network and Distributed Security Symposium (NDSS), Virtual, February 21-25, 2021.

  • Kaiwen Shen, Chuhan Wang, Xiaofeng Zheng, Minglei Guo, Chaoyi Lu, Baojun Liu, Yuxuan Zhao, Shuang Hao, Haixin Duan, Qinfeng Pan and Min Yang. Weak Links in Authentication Chains: A Large-scale Analysis of Email Sender Spoofing Attacks, Proceedings of The 30th USENIX Security Symposium (USENIX Security), Vancouver, BC, Canada, August 11-13, 2021.

  • Mingming Zhang, Xiaofeng Zheng, Kaiwen Shen, Ziqiao Kong, Chaoyi Lu, Yu Wang, Haixin Duan, Shuang Hao, Baojun Liu and Min Yang. Talking with Familiar Strangers: An Empirical Study on HTTPS Context Confusion Attacks, Proceedings of The 27th ACM Conference on Computer and Communications Security (CCS), Orlando, USA, November 9-13, 2020.

  • Yiming Zhang, Baojun Liu, Chaoyi Lu, Zhou Li, Haixin Duan, Shuang Hao, Mingxuan Liu, Ying Liu, Dong Wang and Qiang Li. Lies in the Air: Characterizing Fake-base-station Spam Ecosystem in China, Proceedings of The 27th ACM Conference on Computer and Communications Security (CCS), Orlando, USA, November 9-13, 2020.

  • Xiaofeng Zheng, Chaoyi Lu, Jian Peng, Qiushi Yang, Dongjie Zhou, Baojun Liu, Keyu Man, Shuang Hao, Haixin Duan and Zhiyun Qian. Poison over Troubled Forwarders: A Cache Poisoning Attack Targeting DNS Forwarding Devices, Proceedings of The 29th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 12-14, 2020.

  • Weizhong Li, Kaiwen Shen, Run Guo, Baojun Liu, Jia Zhang, Haixin Duan, Shuang Hao, Xiarun Chen and Yao Wang. CDN Backfired: Amplification Attacks Based on HTTP Range Requests, Proceedings of The 50th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Valencia, Spain, June 29 - July 02, 2020.

  • Ruo Guo, Weizhong Li, Baojun Liu, Shuang Hao, Haixin Duan, Jia Zhang, Kaiwen Shen, Jianjun Chen and Ying Liu. CDN Judo: Breaking the CDN DoS Protection with Itself, Proceedings of The 27th ISOC Network and Distributed System Security Symposium (NDSS), Valencia, Spain, June 29 - July 02, 2020.

  • Chaoyi Lu, Baojun Liu, Zhou Li, Shuang Hao, Haixin Duan, Mingming Zhang, Chunying Leng, Ying Liu, Zaifeng Zhang and Jianping Wu. An End-to-End, Large-Scale Measurement of DNS-over-Encryption: How Far Have We Come? Proceedings of The 2019 Internet Measurement Conference (IMC), Amsterdam, Netherlands, October 21-23, 2019.

  • Kun Du, Hao Yang, Zhou Li, Haixin Duan, Shuang Hao, Baojun Liu, Yuxiao Ye, Mingxuan Liu, Xiaodong Su, Guang Liu, Zhifeng Geng, Zaifeng Zhang and Jinjin Liang. TL;DR Hazard: A Comprehensive Study of Levelsquatting Scams, Proceedings of The 15th International Conference on Security and Privacy On Communication Networks (SecureComm), Orlando, USA, October 23-25, 2019.

  • Baojun Liu, Zhou Li, Peiyuan Zong, Chaoyi Lu, Haixin Duan, Ying Liu, Sumayah Alrwais, XiaoFeng Wang, Shuang Hao, Yaoqi Jia, Yiming Zhang, Kai Chen and Zaifeng Zhang. TraffickStop: Detecting and Measuring Illicit Traffic Monetization Through Large-scale DNS Analysis, Proceedings of The 4th IEEE European Symposium on Security and Privacy (IEEE EuroS&P), Stockholm, Sweden, June 17-19, 2019.

  • Eihal Alowaisheq, Peng Wang, Sumayah Alrwais, Xiaojing Liao, XaioFeng Wang, Tasneem Alowaisheq, XiangHang Mi, Siyuan Tang and Baojun Liu. Cracking Wall of Confinement: Understanding and Analyzing Malicious Domain Takedowns, Proceedings of The 26th ISOC Network and Distributed System Security Symposium (NDSS), San Diego, CA, USA, February 24-27, 2020.

  • Xianghang Mi, Xuan Feng, Xiaojing Liao, Baojun Liu, Xiaofeng Wang, Feng Qian, Zhou Li, Sumayah Alrwais, Limin Sun and Ying Liu. Resident Evil: Understanding Residential IP Proxy as a Dark Service, Proceedings of The 40th IEEE Symposium on Security and Privacy (IEEE S&P), San Francisco, USA, May 20-22, 2019.

  • Run Guo, Jianjun Chen, Baojun Liu, Jia Zhang, Chao Zhang, Haixin Duan, Tao Wan, Jian Jiang, Shuang Hao and Yaoqi Jia. Abusing CDNs for Fun and Profit: Security Issues in CDNs’ Origin Validation, Proceedings of The 37th IEEE International Symposium on Reliable Distributed Systems (SRDS), Bahia, Brazil, October 2-5, 2018.

  • Mingming Zhang, Baojun Liu, Chaoyi Lu, Jia Zhang, Shuang Hao and Haixin Duan. Measuring Privacy Threats in China-Wide Mobile Networks, Proceedings of The 8th USENIX Workshop on Free and Open Communications on the Internet (FOCI), Baltimore, USA, August 14, 2018.

  • Baojun Liu, Chaoyi Lu, Haixin Duan, Ying Liu, Zhou Li, Shuang Hao and Min Yang. Who Is Answering My Queries: Understanding and Characterizing Interception of the DNS Resolution Path, Proceedings of The 27th USENIX Security Symposium (USENIX Security), Baltimore, USA, August 14, 2018.

  • Baojun Liu, Chaoyi Lu, Zhou Li, Ying Liu, Haixin Duan, Shuang Hao and Zaifeng Zhang. A Reexamination of Internationalized Domain Names: the Good, the Bad and the Ugly, Proceedings of The 48th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Luxembourg City, Luxembourg, June 25-28, 2018.

  • Daiping Liu, Zhou Li, Kun Du, Haining Wang, Baojun Liu and Haixin Duan. Don’t Let One Rotten Apple Spoil the Whole Barrel: Towards Automated Detection of Shadowed Domains, Proceedings of The 24th ACM Conference on Computer and Communications Security (CCS), Dallas, TX, October 30 - November 3, 2017.

Teaching

  • “Internet Architecture and Security Fundamentals”, Fall 2023
  • “Network Security Attack and Defense Practices”, Summer 2023
  • “Network Measurement”, Fall 2021.
  • “Network Measurement”, Fall 2020.
  • “Next Generation Internet”, Fall 2020.
  • “Network Measurement”, Fall 2019.
  • “Network Security”, Fall 2019.
  • “Next Generation Internet”, Fall 2019.

Awards and Honors

  • 2023, Top Young Scholar of National “Ten Thousand Talent Program”
  • 2023, Internet Fundamental Technology Archievement Award
  • 2022, ACM SIGSAC China Rising Star
  • 2022, Nominee of Excellence Tsinghua Postdoctoral Researcher
  • 2020, ShuiMu Tsinghua Scholar
  • 2020, IRTF Applied Networking Research Prize (ANRP)
  • 2020, IEEE/IFIP DSN Best Paper Award
  • 2019, NDSS Distinguished Paper Award
  • 2019, IMC Nominee of Distinguished Paper Award and Community Contribution