CoPHish represents an emerging phishing attack vector that exploits Microsoft Copilot Studio chatbots to automate the creation of sophisticated OAuth phishing campaigns. Unlike traditional phishing that relies on generic or poorly crafted messages, CoPHish uses AI-generated content to produce highly convincing and contextually relevant phishing lures. The attack targets the OAuth authorization process, where users are tricked into granting malicious applications access to their accounts. By abusing OAuth consent flows, attackers can obtain tokens that allow them to access sensitive data or services without needing direct credentials. This approach bypasses many traditional security controls that focus on password theft. The technique leverages the chatbot’s ability to generate human-like dialogue and persuasive content, increasing the likelihood of user interaction and consent. Although no direct software vulnerability is exploited, the threat exploits human factors and the trust placed in OAuth permissions. Currently, there are no known exploits in the wild, and the discussion level is minimal, but the potential for widespread campaigns exists given the popularity of Microsoft Copilot Studio and OAuth integrations in enterprise environments. The threat is classified as medium severity due to the reliance on user interaction and the absence of automated exploitation, but the impact on confidentiality and integrity can be significant if successful.

For European organizations, the CoPHish technique poses a significant risk to the confidentiality and integrity of user accounts and corporate data. Successful phishing campaigns can lead to unauthorized access to email, cloud storage, and collaboration tools, resulting in data breaches, intellectual property theft, and potential lateral movement within networks. Organizations heavily reliant on Microsoft 365 and OAuth-based third-party integrations are particularly vulnerable. The impact extends to regulatory compliance, as compromised accounts may lead to violations of GDPR and other data protection laws, incurring fines and reputational damage. The medium severity reflects the fact that exploitation requires user interaction and targeted phishing, but the widespread use of Microsoft cloud services in Europe increases the attack surface. Additionally, the use of AI-generated phishing content may lower the detection rate by traditional email security solutions, increasing the risk of successful compromise.

European organizations should implement targeted user awareness training focused on the risks of OAuth consent phishing and the specific tactics used in CoPHish campaigns. Security teams must enforce strict monitoring and auditing of OAuth app permissions within Microsoft 365 environments, promptly revoking suspicious or unauthorized consents. Deploy advanced email filtering solutions that incorporate AI and behavioral analysis to detect and block AI-generated phishing content. Organizations should also consider implementing conditional access policies that limit OAuth token scopes and require multi-factor authentication (MFA) for sensitive operations. Regularly reviewing and updating OAuth app whitelists and blacklists can reduce exposure to malicious applications. Incident response plans should include procedures for quickly identifying and mitigating OAuth token misuse. Collaboration with Microsoft support and threat intelligence sharing within European cybersecurity communities can enhance detection and response capabilities.