Why CISOs Should Hunt Phishing Campaigns, Not Just Emails

Jan de Vries · 2026-07-30

If you're a CISO, you know the feeling. Your inbox is a firehose of alerts, each one screaming for attention. Analysts are drowning in a sea of individual indicators of compromise, or IOCs. It's exhausting, it's inefficient, and frankly, it's not working. The old way of looking at phishing—one email at a time—is burning out your team and leaving real threats undetected. Let's talk about a better approach. It's about shifting your mindset from chasing single emails to understanding the entire campaign behind them. This isn't just a buzzword; it's a fundamental change in how we defend our networks. ### The Real Problem with IOC Fatigue Think about it. When you focus only on individual IOCs, you're playing whack-a-mole. You block one malicious link, and the attacker simply spins up another. You quarantine one phishing email, and a dozen more variants slip through. Your analysts are stuck in a reactive loop, constantly putting out fires instead of preventing them. IOC fatigue is real. It happens when your team is so overwhelmed by the sheer volume of alerts that they start to tune out. They miss the critical signals hidden in the noise. This isn't a failure of effort; it's a failure of strategy. You're asking them to connect dots that are miles apart without giving them the full picture. ### What Campaign-Based Detection Actually Means Campaign-based detection flips the script. Instead of looking at a single email in isolation, you look at the entire operation. Where did it come from? What infrastructure is it using? Who else is being targeted? What's the end goal? By grouping these related activities together, you see the attack as a whole, not just its individual parts. Here's a simple way to think about it: chasing IOCs is like trying to stop a river by scooping out water with a bucket. Campaign-based analysis is like finding the source of the river and building a dam. It's proactive, not reactive. ### The Clear Benefits for Your Security Team Making this shift pays off in three major ways: - **Better Visibility:** You see the full scope of the attack. This lets you identify all affected users and systems, not just the ones who clicked on the first email. - **Faster Response:** When you understand the campaign, you can block the entire infrastructure at once. This cuts response time from days to hours, or even minutes. - **Reduced Analyst Fatigue:** Your team stops drowning in low-level alerts. They focus on meaningful, strategic work, which boosts morale and retention. ### Making the Transition Work for You So, how do you actually make this happen? It starts with your technology. You need tools that can correlate data across multiple sources, not just your email gateway. Look for solutions that can group phishing attempts by shared infrastructure, like the same sender domain, TLS certificate, or hosting provider. It also requires a change in workflow. Encourage your analysts to ask "who else?" and "what else?" instead of just "what is this?" This mindset shift is crucial. It's about building a narrative around the attack, not just cataloging its components. ### The Bottom Line for Your Security Posture Cofense highlights this exact point: the end of IOC fatigue starts with thinking in campaigns. It's a call to action for every security leader who's tired of the endless cycle of alert, investigate, and remediate. By adopting a campaign-based approach, you're not just improving your security posture; you're investing in the well-being and effectiveness of your team. The shift isn't always easy, but the payoff is undeniable. Your team will be happier, your response times will be faster, and your defenses will be stronger. It's time to stop fighting individual battles and start winning the war against phishing.