Deepak Kumar
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Deepak Kumar has a total of 33 co-authors. Here are the top co-authors by number of shared publications:
- Zakir Durumeric
Stanford University, Stanford, USA
4 shared publications - Seoyoung Kweon
Department of Computer Science and Engineering, University of California San Diego, 9500 Gilman Dr, San Diego, CA, 92093, United States, 1 858-534-2230
3 shared publications - Arshia Arya
University of California, San Diego, San Diego, CA, USA
2 shared publications - Catherine Han
Stanford University, Stanford, California, USA
2 shared publications - Christian Dameff
Department of Emergency Medicine, University of California San Diego, San Diego, CA, United States
2 shared publications - Elisa Tsai
University of Michigan Carnegie Mellon University University of Michigan
2 shared publications
Latest Publications
- Open Access
- 14 November 2026
- Published by Association for Computing Machinery (ACM)
- p. 5836-5850
Designing an Automated Fact-Checking Pipeline for Recent Claims
- 14 November 2026
- Published by Association for Computing Machinery (ACM)
- p. 5836-5850
Open AccessDesigning an Automated Fact-Checking Pipeline for Recent Claims
- Open Access
- 4 November 2026
- Published by JMIR Publications Inc. in Journal of Medical Internet Research
- Vol. 28, e114623
Correction: Unveiling Patient-Level Harms and At-Risk Clinical Groups During Hospital Cyberattacks: Systematic Review of Global Case Studies and Social Media Data
- 4 November 2026
- Published by JMIR Publications Inc. in Journal of Medical Internet Research
- Vol. 28, e114623
Open AccessCorrection: Unveiling Patient-Level Harms and At-Risk Clinical Groups During Hospital Cyberattacks: Systematic Review of Global Case Studies and Social Media Data
- Open Access
- 28 September 2026
- Published by JMIR Publications Inc. in Journal of Medical Internet Research
- Vol. 28, e88257
Unveiling Patient-Level Harms and At-Risk Clinical Groups During Hospital Cyberattacks: Systematic Review of Global Case Studies and Social Media Data
Background: Cyberattacks against health care organizations are rising in frequency and shifting in nature from data theft to intentional denial of care. Objective: This systematic review identifies and characterizes patient-level harms occurring during hospital cyberattacks across international settings, determines which clinical populations are most vulnerable, and compares patient-level harms reported in peer-reviewed case studies with those described in patient and provider narratives on social media. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020, PRISMA-S (Preferred Reporting Items for Systematic Reviews and Meta-Analyses–Search), and the SWiM (Synthesis Without Meta-analysis) reporting guidelines, we searched MEDLINE, Embase, PubMed, Scopus, and Web of Science for peer-reviewed studies published between January 1, 2004, and July 1, 2026 describing cyberattacks affecting clinical care in health care delivery organizations. Quantitative synthesis was not performed because the included studies reported structurally incompatible outcome types for which no common effect measure existed; synthesis without meta-analysis was conducted according to SWiM. In parallel, a Python (Python Software Foundation) pipeline mined 3408 health care–related subreddits for cyberattack terms extracted during the academic review; posts were reviewed by clinical team members to ensure relevance and coded to clinical specialties and technical failure domains. Results: Fifty-nine studies were included, from which 316 patient-level harms were identified across the combined datasets. Two distinct categories of at-risk patients emerged: those harmed by time-criticality, including patients with stroke, cardiac arrest, and major trauma, for whom delays of minutes to hours are clinically decisive; and those harmed by the intersection of digital dependence and potential for rapid clinical decline, including patients with cancer, patients with diabetes, and those dependent on community prescribing. Specific technical failures were linked to distinct clinical consequences, including those stemming from (1) hardware (oncological harms due to compromised linear accelerators), (2) software (risks for patients with fractures due to failures in digital templating software), and (3) networks/connectivity (fetal deaths due to telemetry failures). Social media data exposed wider harms resulting from infrastructural issues, including compromised door access systems preventing life-saving treatment, failures in ward-based alarms, and closed-circuit television (CCTV) affecting staff/patient safety, and disrupted health-at-home services preventing community therapies. Conclusions: Our study is the first to systematically integrate global case study evidence with large-scale social media data to provide a clinically focused synthesis of patient-level harms during health care cyberattacks. The resulting open-source Cyberattack Impacts, Patient Harms & Emergency Response (CIPHER) dataset links technical failure domains to downstream clinical risks across care settings. As cyberattacks on health care organizations continue to rise in frequency and severity, the boundary between cybersecurity and patient safety has become increasingly blurred, demanding unified frameworks that treat digital resilience and clinical preparedness as inseparable expressions of the same obligation to patients.
- 28 September 2026
- Published by JMIR Publications Inc. in Journal of Medical Internet Research
- Vol. 28, e88257
Open AccessUnveiling Patient-Level Harms and At-Risk Clinical Groups During Hospital Cyberattacks: Systematic Review of Global Case Studies and Social Media Data
Background: Cyberattacks against health care organizations are rising in frequency and shifting in nature from data theft to intentional denial of care. Objective: This systematic review identifies and characterizes patient-level harms occurring during hospital cyberattacks across international settings, determines which clinical populations are most vulnerable, and compares patient-level harms reported in peer-reviewed case studies with those described in patient and provider narratives on social media. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020, PRISMA-S (Preferred Reporting Items for Systematic Reviews and Meta-Analyses–Search), and the SWiM (Synthesis Without Meta-analysis) reporting guidelines, we searched MEDLINE, Embase, PubMed, Scopus, and Web of Science for peer-reviewed studies published between January 1, 2004, and July 1, 2026 describing cyberattacks affecting clinical care in health care delivery organizations. Quantitative synthesis was not performed because the included studies reported structurally incompatible outcome types for which no common effect measure existed; synthesis without meta-analysis was conducted according to SWiM. In parallel, a Python (Python Software Foundation) pipeline mined 3408 health care–related subreddits for cyberattack terms extracted during the academic review; posts were reviewed by clinical team members to ensure relevance and coded to clinical specialties and technical failure domains. Results: Fifty-nine studies were included, from which 316 patient-level harms were identified across the combined datasets. Two distinct categories of at-risk patients emerged: those harmed by time-criticality, including patients with stroke, cardiac arrest, and major trauma, for whom delays of minutes to hours are clinically decisive; and those harmed by the intersection of digital dependence and potential for rapid clinical decline, including patients with cancer, patients with diabetes, and those dependent on community prescribing. Specific technical failures were linked to distinct clinical consequences, including those stemming from (1) hardware (oncological harms due to compromised linear accelerators), (2) software (risks for patients with fractures due to failures in digital templating software), and (3) networks/connectivity (fetal deaths due to telemetry failures). Social media data exposed wider harms resulting from infrastructural issues, including compromised door access systems preventing life-saving treatment, failures in ward-based alarms, and closed-circuit television (CCTV) affecting staff/patient safety, and disrupted health-at-home services preventing community therapies. Conclusions: Our study is the first to systematically integrate global case study evidence with large-scale social media data to provide a clinically focused synthesis of patient-level harms during health care cyberattacks. The resulting open-source Cyberattack Impacts, Patient Harms & Emergency Response (CIPHER) dataset links technical failure domains to downstream clinical risks across care settings. As cyberattacks on health care organizations continue to rise in frequency and severity, the boundary between cybersecurity and patient safety has become increasingly blurred, demanding unified frameworks that treat digital resilience and clinical preparedness as inseparable expressions of the same obligation to patients.
- Open Access
- 12 April 2026
- Published by Association for Computing Machinery (ACM)
- p. 6147-6158
Long Story Short: Auditing U.S. Political Polarization in Recommendations for Long- vs. Short-form Videos on YouTube
- 12 April 2026
- Published by Association for Computing Machinery (ACM)
- p. 6147-6158
Open AccessLong Story Short: Auditing U.S. Political Polarization in Recommendations for Long- vs. Short-form Videos on YouTube
- Open Access
- 7 November 2024
- Published by Association for Computing Machinery (ACM) in Proceedings of the ACM on Human-Computer Interaction
- Vol. 8 (CSCW2) , 1-34
PressProtect: Helping Journalists Navigate Social Media in the Face of Online Harassment
Social media has become a critical tool for journalists to disseminate their work, engage with their audience, and connect with sources. Unfortunately, journalists also regularly endure significant online harassment on social media platforms, ranging from personal attacks to doxxing to threats of physical harm. In this paper, we seek to understand how to make social media usable for journalists who face constant digital harassment. To begin, we conduct a set of need-finding interviews with Asian American and Pacific Islander journalists to understand where existing platform tools and newsroom resources fall short in adequately protecting journalists, especially those of marginalized identities. We map journalists' unmet needs to concrete design goals, which we use to build PressProtect, an interface that provides journalists greater agency when engaging with readers on Twitter/X. Through user testing with eight journalists, we evaluate PressProtect and find that participants felt it effectively protected them against harassment and could also generalize to serve other visible and vulnerable groups. We conclude with a discussion of our findings and recommendations for social platforms hoping to build defensive defaults for journalists facing online harassment.
- 7 November 2024
- Published by Association for Computing Machinery (ACM) in Proceedings of the ACM on Human-Computer Interaction
- Vol. 8 (CSCW2) , 1-34
Open AccessPressProtect: Helping Journalists Navigate Social Media in the Face of Online Harassment
Social media has become a critical tool for journalists to disseminate their work, engage with their audience, and connect with sources. Unfortunately, journalists also regularly endure significant online harassment on social media platforms, ranging from personal attacks to doxxing to threats of physical harm. In this paper, we seek to understand how to make social media usable for journalists who face constant digital harassment. To begin, we conduct a set of need-finding interviews with Asian American and Pacific Islander journalists to understand where existing platform tools and newsroom resources fall short in adequately protecting journalists, especially those of marginalized identities. We map journalists' unmet needs to concrete design goals, which we use to build PressProtect, an interface that provides journalists greater agency when engaging with readers on Twitter/X. Through user testing with eight journalists, we evaluate PressProtect and find that participants felt it effectively protected them against harassment and could also generalize to serve other visible and vulnerable groups. We conclude with a discussion of our findings and recommendations for social platforms hoping to build defensive defaults for journalists facing online harassment.
- Open Access
Specious Sites: Tracking the Spread and Sway of Spurious News Stories at Scale
Misinformation, propaganda, and outright lies proliferate on the web, with some narratives having dangerous real-world consequences on public health, elections, and individual safety. However, despite the impact of misinformation, the research community largely lacks automated and programmatic approaches for tracking news narratives across online platforms. In this work, utilizing daily scrapes of 1,334 unreliable news websites, the large-language model MPNet, and DP-Means clustering, we introduce a system to automatically identify and track the narratives spread within online ecosystems. Identifying 52,036 narratives on these 1,334 websites, we describe the most prevalent narratives spread in 2022 and identify the most influential websites that originate and amplify narratives. Finally, we show how our system can be utilized to detect new narratives originating from unreliable news websites and to aid fact-checkers in more quickly addressing misinformation. We release code and data at https://github.com/hanshanley/specious-sites.
Open AccessSpecious Sites: Tracking the Spread and Sway of Spurious News Stories at Scale
Misinformation, propaganda, and outright lies proliferate on the web, with some narratives having dangerous real-world consequences on public health, elections, and individual safety. However, despite the impact of misinformation, the research community largely lacks automated and programmatic approaches for tracking news narratives across online platforms. In this work, utilizing daily scrapes of 1,334 unreliable news websites, the large-language model MPNet, and DP-Means clustering, we introduce a system to automatically identify and track the narratives spread within online ecosystems. Identifying 52,036 narratives on these 1,334 websites, we describe the most prevalent narratives spread in 2022 and identify the most influential websites that originate and amplify narratives. Finally, we show how our system can be utilized to detect new narratives originating from unreliable news websites and to aid fact-checkers in more quickly addressing misinformation. We release code and data at https://github.com/hanshanley/specious-sites.
- Top Cited PapersOpen Access
- 15 November 2023
- Published by Association for Computing Machinery (ACM)
- p. 2785-2799
Do Users Write More Insecure Code with AI Assistants?
AI code assistants have emerged as powerful tools that can aid in the software development life-cycle and can improve developer productivity. Unfortunately, such assistants have also been found to produce insecure code in lab environments, raising significant concerns about their usage in practice. In this paper, we conduct a user study to examine how users interact with AI code assistants to solve a variety of security related tasks. Overall, we find that participants who had access to an AI assistant wrote significantly less secure code than those without access to an assistant. Participants with access to an AI assistant were also more likely to believe they wrote secure code, suggesting that such tools may lead users to be overconfident about security flaws in their code. To better inform the design of future AI-based code assistants, we release our user-study apparatus to researchers seeking to build on our work.
- 15 November 2023
- Published by Association for Computing Machinery (ACM)
- p. 2785-2799
Top Cited PapersOpen AccessDo Users Write More Insecure Code with AI Assistants?
AI code assistants have emerged as powerful tools that can aid in the software development life-cycle and can improve developer productivity. Unfortunately, such assistants have also been found to produce insecure code in lab environments, raising significant concerns about their usage in practice. In this paper, we conduct a user study to examine how users interact with AI code assistants to solve a variety of security related tasks. Overall, we find that participants who had access to an AI assistant wrote significantly less secure code than those without access to an assistant. Participants with access to an AI assistant were also more likely to believe they wrote secure code, suggesting that such tools may lead users to be overconfident about security flaws in their code. To better inform the design of future AI-based code assistants, we release our user-study apparatus to researchers seeking to build on our work.
- Top Cited PapersOpen Access
- 28 September 2023
- Published by Association for Computing Machinery (ACM) in Proceedings of the ACM on Human-Computer Interaction
- Vol. 7 (CSCW2) , 1-33
A Golden Age: Conspiracy Theories' Relationship with Misinformation Outlets, News Media, and the Wider Internet
Do we live in a "Golden Age of Conspiracy Theories?" In the last few decades, conspiracy theories have proliferated on the Internet with some having dangerous real-world consequences. A large contingent of those who participated in the January 6th attack on the US Capitol believed fervently in the QAnon conspiracy theory. In this work, we study the relationships amongst five prominent conspiracy theories (QAnon, COVID, UFO/Aliens, 9/11, and Flat-Earth) and each of their respective relationships to the news media, both mainstream and fringe. Identifying and publishing a set of 755 different conspiracy theory websites dedicated to our five conspiracy theories, we find that each of them often hyperlinks to the same external domains, with COVID and QAnon conspiracy theory websites having the strongest connections. Examining the role of news media, we further find that not only do outlets known for spreading misinformation hyperlink to our set of conspiracy theory websites more often than mainstream websites but this hyperlinking has increased dramatically between 2018 and 2021, with the advent of QAnon and the start of COVID-19 pandemic. Using partial Granger-causality, we uncover several positive correlative relationships between the hyperlinks from misinformation websites and the popularity of conspiracy theory websites, suggesting the prominent role that misinformation news outlets play in popularizing many conspiracy theories.
- 28 September 2023
- Published by Association for Computing Machinery (ACM) in Proceedings of the ACM on Human-Computer Interaction
- Vol. 7 (CSCW2) , 1-33
Top Cited PapersOpen AccessA Golden Age: Conspiracy Theories' Relationship with Misinformation Outlets, News Media, and the Wider Internet
Do we live in a "Golden Age of Conspiracy Theories?" In the last few decades, conspiracy theories have proliferated on the Internet with some having dangerous real-world consequences. A large contingent of those who participated in the January 6th attack on the US Capitol believed fervently in the QAnon conspiracy theory. In this work, we study the relationships amongst five prominent conspiracy theories (QAnon, COVID, UFO/Aliens, 9/11, and Flat-Earth) and each of their respective relationships to the news media, both mainstream and fringe. Identifying and publishing a set of 755 different conspiracy theory websites dedicated to our five conspiracy theories, we find that each of them often hyperlinks to the same external domains, with COVID and QAnon conspiracy theory websites having the strongest connections. Examining the role of news media, we further find that not only do outlets known for spreading misinformation hyperlink to our set of conspiracy theory websites more often than mainstream websites but this hyperlinking has increased dramatically between 2018 and 2021, with the advent of QAnon and the start of COVID-19 pandemic. Using partial Granger-causality, we uncover several positive correlative relationships between the hyperlinks from misinformation websites and the popularity of conspiracy theory websites, suggesting the prominent role that misinformation news outlets play in popularizing many conspiracy theories.
- Open Access
- 1 July 2023
- Published by Privacy Enhancing Technologies Symposium Advisory Board in Proceedings on Privacy Enhancing Technologies
- Vol. 2023 (3) , 122-137
CERTainty: Detecting DNS Manipulation at Scale using TLS Certificates
DNS manipulation is an increasingly common technique used by censors and other network adversaries to prevent users from accessing restricted Internet resources and hijack their connections. Prior work in detecting DNS manipulation relies largely on comparing DNS resolutions with trusted control results to identify inconsistencies. However, the emergence of CDNs and other cloud providers practicing content localization and load balancing leads to these heuristics being inaccurate, paving the need for more verifiable signals of DNS manipulation. In this paper, we develop a new technique, CERTainty, that utilizes the widely established TLS certificate ecosystem to accurately detect DNS manipulation, and obtain more information about the adversaries performing such manipulation. We find that untrusted certificates, mismatching hostnames, and blockpages are powerful proxies for detecting DNS manipulation. Our results show that previous work using consistency-based heuristics is inaccurate, allowing for 72.45% false positives in the cases detected as DNS manipulation. Further, we identify 17 commercial DNS filtering products in 52 countries, including products such as SafeDNS, SkyDNS, and Fortinet, and identify the presence of 55 ASes in 26 countries that perform ISP-level DNS manipulation. We also identify 226 new blockpage clusters that are not covered by previous research. We are integrating techniques used by CERTainty into active measurement platforms to continuously and accurately monitor DNS manipulation.
- 1 July 2023
- Published by Privacy Enhancing Technologies Symposium Advisory Board in Proceedings on Privacy Enhancing Technologies
- Vol. 2023 (3) , 122-137
Open AccessCERTainty: Detecting DNS Manipulation at Scale using TLS Certificates
DNS manipulation is an increasingly common technique used by censors and other network adversaries to prevent users from accessing restricted Internet resources and hijack their connections. Prior work in detecting DNS manipulation relies largely on comparing DNS resolutions with trusted control results to identify inconsistencies. However, the emergence of CDNs and other cloud providers practicing content localization and load balancing leads to these heuristics being inaccurate, paving the need for more verifiable signals of DNS manipulation. In this paper, we develop a new technique, CERTainty, that utilizes the widely established TLS certificate ecosystem to accurately detect DNS manipulation, and obtain more information about the adversaries performing such manipulation. We find that untrusted certificates, mismatching hostnames, and blockpages are powerful proxies for detecting DNS manipulation. Our results show that previous work using consistency-based heuristics is inaccurate, allowing for 72.45% false positives in the cases detected as DNS manipulation. Further, we identify 17 commercial DNS filtering products in 52 countries, including products such as SafeDNS, SkyDNS, and Fortinet, and identify the presence of 55 ASes in 26 countries that perform ISP-level DNS manipulation. We also identify 226 new blockpage clusters that are not covered by previous research. We are integrating techniques used by CERTainty into active measurement platforms to continuously and accurately monitor DNS manipulation.
- Open Access
CERTainty: Detecting DNS Manipulation at Scale using TLS Certificates
DNS manipulation is an increasingly common technique used by censors and other network adversaries to prevent users from accessing restricted Internet resources and hijack their connections. Prior work in detecting DNS manipulation relies largely on comparing DNS resolutions with trusted control results to identify inconsistencies. However, the emergence of CDNs and other cloud providers practicing content localization and load balancing leads to these heuristics being inaccurate, paving the need for more verifiable signals of DNS manipulation. In this paper, we develop a new technique, CERTainty, that utilizes the widely established TLS certificate ecosystem to accurately detect DNS manipulation, and obtain more information about the adversaries performing such manipulation. We find that untrusted certificates, mismatching hostnames, and blockpages are powerful proxies for detecting DNS manipulation. Our results show that previous work using consistency-based heuristics is inaccurate, allowing for 72.45% false positives in the cases detected as DNS manipulation. Further, we identify 17 commercial DNS filtering products in 52 countries, including products such as SafeDNS, SkyDNS, and Fortinet, and identify the presence of 55 ASes in 26 countries that perform ISP-level DNS manipulation. We also identify 226 new blockpage clusters that are not covered by previous research. We are integrating techniques used by CERTainty into active measurement platforms to continuously and accurately monitor DNS manipulation.
Open AccessCERTainty: Detecting DNS Manipulation at Scale using TLS Certificates
DNS manipulation is an increasingly common technique used by censors and other network adversaries to prevent users from accessing restricted Internet resources and hijack their connections. Prior work in detecting DNS manipulation relies largely on comparing DNS resolutions with trusted control results to identify inconsistencies. However, the emergence of CDNs and other cloud providers practicing content localization and load balancing leads to these heuristics being inaccurate, paving the need for more verifiable signals of DNS manipulation. In this paper, we develop a new technique, CERTainty, that utilizes the widely established TLS certificate ecosystem to accurately detect DNS manipulation, and obtain more information about the adversaries performing such manipulation. We find that untrusted certificates, mismatching hostnames, and blockpages are powerful proxies for detecting DNS manipulation. Our results show that previous work using consistency-based heuristics is inaccurate, allowing for 72.45% false positives in the cases detected as DNS manipulation. Further, we identify 17 commercial DNS filtering products in 52 countries, including products such as SafeDNS, SkyDNS, and Fortinet, and identify the presence of 55 ASes in 26 countries that perform ISP-level DNS manipulation. We also identify 226 new blockpage clusters that are not covered by previous research. We are integrating techniques used by CERTainty into active measurement platforms to continuously and accurately monitor DNS manipulation.