Why CISOs Should Hunt Phishing Campaigns, Not Just Emails

Jan de Vries · 2026-07-30

Every day, security teams drown in a flood of isolated email alerts. Each one looks like a separate incident, a lone indicator of compromise (IOC) demanding attention. But here's the uncomfortable truth: most of these aren't isolated events. They're pieces of a larger, coordinated attack. And until you start seeing the whole picture, you'll keep fighting the same battles over and over. That's the core argument behind campaign-based phishing detection, a concept that's gaining serious traction among security leaders. Instead of reacting to individual malicious emails, you group them into campaigns based on shared characteristics—the same sender infrastructure, similar payloads, or identical lures. This shift doesn't just improve visibility; it changes the entire game for your analysts. ### The Real Cost of IOC Fatigue Think about what your team does right now. A phishing email slips past the gateway. An alert fires. An analyst opens a ticket, investigates the single email, and maybe blocks the sender. Case closed, right? Not really. The same attacker simply spins up a new domain and sends the same campaign to a different department. This cycle creates what experts call IOC fatigue. Your analysts burn out chasing ghosts. They're constantly reacting to symptoms, never addressing the disease. The average security operations center (SOC) receives thousands of alerts daily, and a massive chunk of those are phishing-related. When everything looks urgent, nothing feels urgent. That's when critical alerts slip through the cracks. Campaign-based thinking breaks this loop. By grouping related threats, you stop treating each email as a unique event. Instead, you see the attacker's playbook. You understand their infrastructure, their timing, and their targets. That broader view lets you neutralize an entire campaign with one decisive action, rather than playing whack-a-mole for weeks. ### Better Visibility, Faster Response Here's how it works in practice. Instead of asking "What is this email?" you ask "What is this campaign trying to achieve?" The first question leads to a single investigation. The second leads to a strategic response. You might identify that a campaign targets your finance team with fake invoice lures every Tuesday at 10 AM. Now you can proactively block the infrastructure, alert your finance staff, and update your email filters before the next wave hits. This approach also accelerates response times dramatically. When you detect a campaign, you can automatically quarantine all related emails across your entire environment. You don't need to manually review each one. Your analysts can focus on the handful of campaigns that actually pose a threat, not the hundreds of emails that share the same malicious DNA. Consider the math. If you process 500 phishing alerts a day and group them into 10 campaigns, you've just reduced your analyst's workload by 98%. That's not just efficiency; it's a lifeline for a burned-out team. ### From Reactive to Proactive The beauty of campaign thinking is that it moves you from reactive to proactive. You're no longer waiting for the next attack. You're mapping out the threat landscape and anticipating the attacker's next move. This is how you build a defense that actually holds. One security leader I spoke with put it simply: "We stopped chasing emails and started hunting campaigns. Within a month, our response times dropped by half, and our analysts actually had time to think." That's the outcome every CISO wants. ### The Bottom Line Phishing isn't going away. But your approach to it can evolve. By thinking in campaigns, not individual emails, you give your team the visibility they need to see the whole battlefield. You accelerate response, reduce fatigue, and finally get ahead of the attackers. The shift isn't just a technical improvement—it's a cultural one that empowers your analysts to work smarter, not harder. So, take a hard look at your current detection strategy. Are you still drowning in isolated IOCs? If so, it's time to zoom out. Your team—and your organization's security posture—will thank you.