Distributed Denial of Service (DDoS) attacks pose a growing threat to global cybersecurity, overwhelming networks and causing substantial economic and reputational damage. While prior research has emphasized technical mitigations, this study investigates the role of cultural tightness in shaping national resilience to DDoS attacks. Using a generalized linear mixed-effects model on 12 years of data from 57 countries, we find that tighter cultures experience fewer DDoS attacks, with population size and density further moderating this effect. These findings highlight the importance of cultural norms in cybersecurity and suggest policy implications for integrating cultural factors into national cyber-defense strategies.