How ‘Reprompt’ Attack Let Hackers Steal Data From Microsoft Copilot

Varonis found a “Reprompt” attack that let a single link hijack Microsoft Copilot Personal sessions and exfiltrate data; Microsoft patched it in January 2026.

How a simple link allowed hackers to bypass Copilot's security guardrails - and what Microsoft did about it

Reprompt impacted Microsoft Copilot Personal and, according to the team, gave "threat actors an invisible entry point to perform a data‑exfiltration chain that bypasses enterprise security controls ...
IEEE

Multistep Identification of the DFIG Model Based on Dynamic Analysis of Parameter Identifiability

Abstract: Accurate model parameters are crucial for power system simulation analysis and control design. However, it is challenging to identify complex models owing to the implicit correlation between ...

This Microsoft Copilot AI attack took a single click to compromise users

Security researchers Varonis have discovered Reprompt, a new way to perform prompt-injection style attacks in Microsoft ...

Microsoft Copilot AI attack took just a single click to compromise users - here's what we know

Security researchers Varonis have discovered Reprompt, a new way to perform prompt-injection style attacks in Microsoft ...

A single click mounted a covert, multistage attack against Copilot

Microsoft has fixed a vulnerability in its Copilot AI assistant that allowed hackers to pluck a host of sensitive user data ...

Reprompt attack hijacked Microsoft Copilot sessions for data theft

Researchers identified an attack method dubbed "Reprompt" that could allow attackers to infiltrate a user's Microsoft Copilot session and issue commands to exfiltrate sensitive data.