CrowdStrike 2025 Threat Hunting Report – Part 9: Vulnerability Hunting
- Katarzyna Celińska
- 20 minutes ago
- 2 min read
One of the most pressing findings from this year’s report is how vulnerabilities remain the fastest path to compromise. In 2024, 52% of vulnerabilities observed were related to initial access, with adversaries overwhelmingly exploiting internet-exposed applications to get their first foothold.
The Zero-Day Challenge
Attackers are no longer waiting weeks or months to weaponize flaws — they’re doing it within hours or days of disclosure. Groups like GRACEFUL SPIDER exemplify this trend:
✅ They exploited a zeroday vulnerability in Cleo data transfer products in December 2024, bypassing recently released patches.
✅ Within minutes of detection, defenders were alerted; within hours, global hunting patterns were deployed to stop malicious file writes.
✅ By December 11, when the exploit was publicly released, opportunistic attackers were already attempting to replicate it at scale.

This illustrates how patch circumvention is now a standard adversary technique: even when vendors release fixes, determined actors quickly find ways around them.
Key Observations
✅ Adversaries chain exploits → Combining multiple flaws to escalate privileges and bypass defenses.
✅ Zero-days are monetized quickly → First by sophisticated groups, then by the broader eCrime ecosystem once proof-of-concepts are published.
✅ Critical infrastructure risk → Exploits are disproportionately aimed at VPNs, web apps, and cloud-facing services.
✅ Defensive hunting matters → Even when no patch exists, proactive hunting for post-exploitation behavior provides a fail-safe against mass exploitation.
Vulnerability hunting is no longer about “patch and forget.” It’s about detecting what slips through in the critical window before a fix is available. The report makes it clear: adversaries innovate fast, but defenders can win by combining exposure management, proactive hunting, and intelligence-led defense.
My recommendation:
✅ Prioritize patching internet-facing systems — especially VPN gateways, cloud applications, and web servers.
✅ Continuously assess exposure through vulnerability scanning and asset inventory.
✅ Hunt for exploitation artifacts, such as anomalous file writes, suspicious PowerShell/command execution, and abnormal process behavior.
✅ Integrate threat intelligence with detection to identify exploit chaining and evolving zero-day campaigns.
Author: Sebastian Burgemejster
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