Researchers discovered a serious flaw in Microsoft's Copilot that let hackers steal personal data through a simple link. The exploit required only one click to execute, even if the user closed the chat.
Vulnerability in Microsoft Copilot
Attack executed with one click
Research by Varonis security team
Data included sensitive user info
Bypassed security software
Instructions hidden in a URL
Microsoft’s Copilot had a significant security flaw that hackers exploited. They accessed sensitive user info, including names and locations, with just one click on a malicious link. White-hat researchers from Varonis conducted the attack, exposing how even enterprise-level security measures were circumvented. Once the link had been clicked, the data theft proceeded without further user interaction, even if the Copilot chat was closed.
How the Attack Worked
The operation was brief yet effective. According to Varonis researcher Dolev Taler, “Once we deliver this link… the user just has to click on the link and the malicious task is immediately executed.” This means that the attack could seamlessly engage without requiring additional effort from the user.
The link led to a secure Varonis-controlled domain. It included detailed instructions, allowing Copilot to transfer personal details through web requests upon being accessed. The goal was to extract sensitive user information without the target ever realizing it was happening.
Details of the Data Breach
What’s alarming is the level of detail hackers gained. They not only accessed a user’s secret (“HELLOWORLD1234!”) but also gathered further personal data like the user’s name and location. This information was passed along via hidden requests embedded in the Copilot’s operations, amplifying the attack’s impact.
Hacker-used malicious prompt
Exfiltrated user secrets
Data sent to Varonis’ server
Further exploits hidden in a .jpg
Compiled commands to gather user data
Chat session closure didn’t stop attacks
Impact of the Exploit
This incident raises questions about the effectiveness of security protocols. The breach’s ability to bypass existing enterprise-level endpoint protection is concerning for both users and companies that rely on such technologies to safeguard sensitive data.
With security flaws like this on the table, tech companies must reassess their defensive strategies to better protect user information. The rapid pace of technological advancement emphasizes the need for ongoing vigilance against potential threats.
Luca Fischer is a senior technology journalist with more than twelve years of professional experience specializing in artificial intelligence, cybersecurity, and consumer electronics. L. Fischer earned his M.S. in Computer Science from Columbia University in 2011, where he developed a strong foundation in data science and network security before transitioning into tech media.
Throughout his career, Luca has been recognized for his clear, analytical approach to explaining complex technologies. His in-depth articles explore how AI innovations, privacy frameworks, and next-generation devices impact both industry and society.
Luca’s work has appeared across leading digital publications, where he delivers detailed reviews, investigative reports, and feature analyses on major players such as Google, Microsoft, Nvidia, AMD, Intel, OpenAI, Anthropic, and Perplexity AI.
Beyond writing, he mentors young journalists entering the AI-tech field and advocates for transparent, ethical technology communication. His goal is to make the future of technology understandable and responsible for everyone.
Ars Technica was launched in 1998 by Ken Fisher and Jon Stokes as a space where engineers, coders, and hard-core enthusiasts could find news that respected their intelligence.
From the start it rejected shallow churn, instead publishing 5 000-word CPU micro-architecture briefs, line-by-line Linux kernel diffs, and forensic GPU teardowns that treat readers like fellow engineers rather than casual shoppers.
Condé Nast acquired the site in 2008, yet the newsroom retained its autonomy, keeping the beige-and-black design ethos and the Latin tagline “Art of Technology.”
Today its staff physicists, former network architects, and defunct-astronaut hopefuls explain quantum supremacy papers, dissect U.S. spectrum auctions, benchmark every new console, and still find time to live-blog Supreme Court tech policy arguments.
The result is a community whose comment threads read like peer-review sessions: voltage curves are debated, errata are crowdsourced overnight, and authors routinely append “Update” paragraphs that credit readers for spotting a mis-stated opcode.
