The identified threat involves malicious browser extensions targeting the Comet and Atlas browsers, which are specialized browsers integrating AI sidebar functionalities. Attackers create fake AI sidebars that visually and functionally mimic legitimate AI model responses, deceiving users into interacting with them under false pretenses. These fake sidebars can capture sensitive user inputs, including confidential queries or data, effectively stealing information without the user's knowledge. The attack leverages the trust users place in AI interfaces and the relative novelty of AI sidebar features, which may lack robust verification mechanisms. The threat does not exploit a traditional software vulnerability but rather abuses the extension ecosystem and user trust. No specific affected versions or patches are currently identified, and no known exploits have been observed in the wild, indicating this is a proof-of-concept or emerging threat. The attack requires the user to install a malicious extension, highlighting the importance of social engineering or supply chain compromise. The threat's medium severity reflects moderate impact potential and exploitation complexity. The detailed Kaspersky blog article (https://www.kaspersky.com/blog/ai-sidebar-spoofing-atlas-comet/54769/) provides an in-depth technical analysis of the spoofing techniques and user deception methods. This threat underscores the risks introduced by integrating AI features into browsers without stringent security controls and user verification mechanisms.

For European organizations, this threat poses a risk primarily to confidentiality, as sensitive data entered into fake AI sidebars can be exfiltrated by attackers. Organizations relying on Comet and Atlas browsers for AI-assisted workflows or data processing may inadvertently expose proprietary or personal information. The integrity of user interactions is compromised, as users receive spoofed AI responses that could mislead decision-making or workflow processes. Availability is less impacted since the attack focuses on data theft rather than service disruption. The requirement for user installation of malicious extensions limits the attack scope but also highlights the risk of insider threats or successful phishing campaigns. European organizations with less mature cybersecurity awareness or lax extension policies are more vulnerable. The threat could lead to regulatory compliance issues under GDPR if personal data is leaked. Additionally, trust in AI tools and browser security may erode, affecting digital transformation initiatives. The absence of known exploits in the wild provides a window for preemptive mitigation before widespread impact occurs.

1. Enforce strict policies on browser extension installations, allowing only vetted and trusted extensions in Comet and Atlas browsers. 2. Educate users about the risks of installing unverified extensions and the importance of verifying AI sidebar authenticity, including checking for official sources and digital signatures. 3. Implement monitoring and anomaly detection for unusual data flows from browsers, focusing on potential exfiltration patterns linked to AI sidebar interactions. 4. Encourage the use of endpoint security solutions capable of detecting malicious extensions or suspicious browser behaviors. 5. Collaborate with Comet and Atlas browser vendors to advocate for enhanced extension vetting, AI sidebar verification mechanisms, and security updates. 6. Develop internal guidelines for verifying AI responses, possibly integrating secondary verification tools or alerts when interacting with AI sidebars. 7. Regularly audit browser configurations and installed extensions across organizational devices to identify and remove unauthorized components. 8. Prepare incident response plans specific to AI sidebar spoofing scenarios, including containment and forensic analysis procedures.