Dear colleagues, Last weekend, RIPE NCC Access, our single sign-on (SSO) service was affected by what appears to be a deliberate ‘credential-stuffing’ attack, which caused some downtime. We mitigated the attack, and we are now taking steps to ensure that our services are better protected against such threats in the future. Our preliminary investigations do not indicate that any SSO accounts have been compromised. If we do find that an account has been affected in the course of our investigations, we will contact the account holder individually to inform them. We would like to ask you to enable two-factor authentication on your RIPE NCC Access account if you have not already done so to ensure that your account is secure. In general, using two-factor authentication across all your accounts can help limit your exposure to such attacks. We will keep you informed about any relevant developments. If you have noticed any suspicious activity in your RIPE NCC Access account, please contact us immediately at security@ripe.net. Best regards, Ivo Dijkhuis Senior Information Security Officer, RIPE NCC