A cybersecurity researcher finds that a zero-day exploit has a 15% chance of breaching a system per attempt. If an attacker makes 5 independent attempts, what is the probability (as a percentage) that at least one breach occurs?

Sun, 03 May 2026 09:20:14 +0000

**The Hidden Risk of Repeated Cyber Attacks: What One Researcher’s Findings Reveal** In a world where digital threats evolve faster than firewalls keep up, a crucial question lingers: how likely is a successful breach when attackers strike multiple times? Recent analysis by a cybersecurity researcher reveals a stark reality—each independent attempt carries a 15% chance of compromising a system. With just five such attempts, what’s the real risk that an attacker successfully breaches defenses? Understanding this probability isn’t just about fear of exposure—it’s about awareness in the face of routine cyber probing, a growing concern for individuals and enterprises alike. When a researcher examines zero-day exploits—unpatched vulnerabilities unknown to vendors—their modeling shows independence between attack attempts. Each one represents a fresh, untargeted entry point, with a 15% leverage. This means every brush against a system isn’t guaranteed success, but the cumulative effect shifts the risk dramatically. So, what does math say about five such independent probes? The answer reshapes how we think about digital safeguarding. **Why This Researcher’s Findings Are Gaining Attention**