Antivirus Isn't Dead—It's Your First Responder. Here's the Real IR Play

When the CrowdStrike 2026 Global Threat Report says 82% of detections in 2025 were malware-free, you'd be forgiven for thinking antivirus is a paperweight. But that's a misread. In incident response, we don't get to pick between AV and EDR—we need both, but we need them in the right order. Let's bust the myths that are quietly sabotaging your IR plan.

If 82% of attacks are malware-free, why keep antivirus around?

Because that 82% isn't the whole story. Yes, attackers are living off the land, using PowerShell, WMI, and stolen credentials—no malicious files dropped. But the other 18% still uses malware, and commodity ransomware isn't extinct. Antivirus is your tripwire for that 18%. It catches the known stuff instantly, at the point of entry, before it can spread. EDR is your detective for the 82%—it watches behavior, spots anomalies, and can isolate a host mid-attack. As CISA's endpoint detection and response guidance puts it, antivirus is prevention-focused, while EDR is detection and response. You don't run them as rivals; you run AV as the first filter, EDR as the deep dive.

What does 'malware-free' actually mean for my IR playbook?

It means your IR playbook can't start with 'find the malicious file.' In 2024, 79% of detections were malware-free, and average breakout time was 48 minutes (CrowdStrike 2025 Global Threat Report). By 2025, breakout time dropped to 29 minutes (CrowdStrike 2026 Global Threat Report). That's not a stat to admire; it's a deadline. If you're waiting for an AV alert, you're already dead. Your IR plan needs to assume a user clicked a bad link or a vulnerability was exploited—Verizon's 2026 DBIR found that vulnerability exploitation has overtaken stolen passwords as the top initial access vector. So your first move isn't scanning for signatures; it's checking for anomalous behavior, privileged account use, and lateral movement. That's EDR territory, but AV still has a role: it blocks the known malware that would otherwise give you a false sense of 'normal.'

Should I drop antivirus if I have EDR? (The myth we need to kill)

No. That's like asking if you should drop your smoke detectors because you have a fire department. CISA's guidance is explicit: most organizations should run antivirus alongside EDR, letting EDR focus on sophisticated threats rather than commodity malware noise. The reality is that AV catches the boring stuff—the phishing attachment that everyone's seen—so your SOC isn't drowning in alerts. EDR catches the clever stuff. If you drop AV, you're forcing EDR to be your first line, which means more alert fatigue, more missed signals. The two are complementary, not competing. CISA's comparison table says it plainly: AV is limited to quarantining or deleting matched files; EDR can isolate endpoints, terminate processes, capture forensics, and roll back changes. That's not a reason to ditch AV—it's a reason to use both.

How do I actually run AV and EDR together without tripping over each other?

You configure them as layers, not rivals. Let EDR be the primary alert source—it's behavioral, so it catches the weird stuff. Let AV be the background cleaner—it scans files, blocks known malware, and keeps the noise down. In practice, you set AV to auto-quarantine and only alert on high-confidence detections. EDR you tune to alert on behaviors: credential dumping, unusual PowerShell, lateral movement. When an alert fires, you investigate. The key is to avoid duplicate alerts—many EDRs can ingest AV logs and correlate. For example, if AV blocks a file and EDR sees a process spawning from a weird parent, you want one incident, not two. That's where XDR helps, as Cisco notes: XDR correlates telemetry across endpoints, identity, email, and cloud. But even without XDR, you can write a simple playbook: AV alert → check EDR timeline → decide if it's a false positive or a real attack.

What's the first thing I should do when an alert fires?

Contain, don't delete. EDR's superpower is isolation—you can quarantine a host in seconds, freezing the attacker in place. Then you investigate: what did the user do? What processes ran? What did the attacker touch? AV would have just deleted a file and moved on, which is fine for a one-off, but in a real attack, the file is just the tip. You need the forensics—that's EDR. And don't forget the human factor: IBM's 2026 report found a 56% increase in AI-driven attacks, including deepfake impersonations. So when an alert fires, ask: did someone get tricked into giving away credentials? That's not something AV or EDR catches alone—it's a people problem. Train your staff, use MFA, and have a plan. Verizon's DBIR recommends exactly that: multi-factor authentication, keeping software updated, and having an incident response plan.

What about zero trust? Isn't that the real answer?

Zero trust is the philosophy, not the tool. NIST SP 800-207 defines zero trust as 'never trust, always verify'—explicit verification, least privilege, assume breach. That's a great framework, and it changes how you architect your network. But it doesn't replace AV or EDR; it complements them. Cisco's take: EDR is reactive and detective, while zero trust is proactive and preventive. You need both. Zero trust says 'don't trust any device, even inside the network'—so you verify every request. EDR says 'if something gets through, catch it and respond.' The two work together: zero trust limits what an attacker can access, and EDR catches the attacker when they try to move. In IR, zero trust means you've already segmented your network, so a breach on one host doesn't become a breach of everything. That's your best defense, plus AV and EDR as your safety nets.

So what's the bottom line for my IR plan?

Stop treating AV and EDR as either/or. Run both, with clear roles: AV blocks the known, EDR detects the unknown. Practice your IR playbook with the 29-minute breakout time in mind—if you can't contain a host within that window, you're losing. Use the CISA KEV catalog to patch the vulnerabilities attackers are actively exploiting—as of August 2026, that's about 1,670 of them, and Verizon says vulnerability exploitation is the top initial access vector. And don't forget the human layer: AI-driven attacks are rising, so train your people and use MFA. The takeaway is simple: AV is your first responder, EDR is your detective, zero trust is your building design. You need all three.

Sources

• CISA - https://www.cisa.gov/stopransomware
• CrowdStrike 2026 Global Threat Report - https://www.crowdstrike.com/en-us/global-threat-report/
• NIST SP 800-207 - https://doi.org/10.6028/NIST.SP.800-207
• IBM Cost of a Data Breach Report 2026 - https://www.ibm.com/reports/data-breach
• Verizon 2026 Data Breach Investigations Report - https://www.verizon.com/business/resources/reports/dbir/
• CISA Known Exploited Vulnerabilities Catalog - https://www.cisa.gov/known-exploited-vulnerabilities-catalog