A new report from CyberSecurityNews has highlighted a chilling reality: attackers have once again bypassed Microsoft’s built-in antivirus, Windows Defender, using a combination of direct syscalls and XOR encryption.
The demonstration, conducted by security researchers, underscores a growing concern—traditional antivirus and endpoint detection solutions are no longer reliable as stand-alone protections.
What does this mean for businesses relying on mainstream security tools? It means that cybercriminals are now routinely developing malware that slips past even well-regarded security defenses without raising alarms. For small and mid-sized businesses, the implication is clear: it’s not a matter of if but when a breach will occur—unless a more proactive security posture is adopted.
In the reported case, researchers crafted an evasive malware sample that successfully ran on a fully updated Windows system without triggering Defender. They achieved this by executing system calls directly (direct syscalls), bypassing the security APIs that Defender monitors. They further obfuscated their activity by using XOR encryption, ensuring payloads remained undetected throughout the attack chain.
The result? The malicious program ran as intended—undetected, unchallenged, and unrestricted.
This technique isn’t just theoretical. It’s already being used in the wild by sophisticated attackers—and eventually, it trickles down into the hands of ransomware gangs and commodity malware authors.
The cybersecurity industry has largely been built around the model of "Detect and Respond." The idea is that systems will monitor behavior, identify anomalies, and flag or contain threats once they've been detected. But what happens when a threat can’t be detected?
That's exactly what happened in this case. The malware bypassed the detection phase entirely, rendering any “response” irrelevant.
This isn’t an isolated incident. It's a sign of a broader trend: adversaries are now routinely developing malware that is intentionally designed to be invisible to EDR (Endpoint Detection and Response) systems. Whether it’s through direct syscalls, encryption, or abusing legitimate tools (like PowerShell or DLL sideloading), the old “detect and respond” model is struggling to keep up.
It’s time for businesses to stop playing defense with outdated strategies. Instead of relying on tools that hope to spot malicious activity, it’s time to adopt solutions that prevent it from executing in the first place.
That’s exactly what AppGuard does.
AppGuard operates on a fundamentally different principle: isolation and containment. Instead of scanning for known bad behaviors, AppGuard assumes that any untrusted process or file could be malicious—and isolates it accordingly. Even if a malware sample is completely novel and undetectable by conventional means (as in the Windows Defender bypass), AppGuard’s patented approach ensures it can’t execute harmful actions or spread.
This isn’t theoretical. AppGuard has a proven 10-year track record in high-security government and enterprise environments—and it’s now available for commercial use. It stops threats before they even start, no matter how advanced, stealthy, or deceptive they are.
If you're a business owner relying on traditional antivirus or even an EDR solution, understand this: the threat landscape has evolved, but most defensive strategies haven’t. Attacks like the one detailed in the CyberSecurityNews article are becoming more frequent, more effective, and more damaging.
Detection isn’t enough anymore. Prevention must be your new priority.
It’s time to make the shift—from “Detect and Respond” to “Isolation and Containment.”
Talk to us at CHIPS about how AppGuard can prevent incidents like this one before they ever have a chance to begin. Let’s make sure your business is protected by a solution designed for today’s threats—not yesterday’s.
👉 Contact us today to learn more about AppGuard and how it can safeguard your organization.
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