Despite extensive guidance from national authorities, several prominent UK organizations have recently suffered significant cyber attacks. Incidents at Colt Technology Services, Marks & Spencer, and Flutter Entertainment demonstrate that adherence to security policies does not automatically equate to effective threat detection, particularly when it comes to detecting attacker tradecraft that evades traditional security tools.
Recent Breaches in Context
The UK’s National Cyber Security Centre (NCSC) has published actionable guidance on mitigating exploitation of known vulnerabilities, most notably CVE-2025-53770 and CVE-2025-53771, both affecting on-premises Microsoft SharePoint instances.
Just weeks before the Colt Technology Services breach, the NCSC issued explicit recommendations, including:
- Immediate patching
- Rotation of SharePoint machine keys
- Deployment of Microsoft Defender for Endpoint or equivalent endpoint threat detection
Nevertheless, the Warlock ransomware group reportedly exfiltrated large volumes of sensitive data from Colt via what researchers suspect to be an unpatched SharePoint server.
In parallel, Marks & Spencer disclosed a ransomware attack facilitated through social engineering targeting a third-party provider. Flutter Entertainment confirmed the compromise of up to 800,000 user records, placing customers at increased risk of spear-phishing and identity fraud.
While the root causes differ, a common thread emerges: Attackers are succeeding not through novel malware, but through the misuse of legitimate tools, living-off-the-land techniques, and artifacts traditional tools overlook.
The Problem with Relying on Policy Alone
Security policies, patching regimes, and endpoint detection platforms are foundational. But they are not sufficient in isolation, especially when adversaries exploit trusted tools, rename binaries, or establish persistence without deploying detectable payloads.
These attacks highlight detection gaps in:
- Renamed dual-use tools (e.g., p.exe = PsExec)
- Web shells in obscure or legitimate-looking directions
- File system anomalies, such as system binaries in incorrect locations
- Malware-less persistence mechanisms (e.g., registry hijacking, scheduled tasks)
These techniques are designed to blend into legitimate system activity. Antivirus and EDR products (built primarily for known malware or behavioral anomalies) often fail to identify such artifacts reliably.
Why Compromise Assessments Matter
Rather than relying on assumptions or alerts, compromise assessments provide empirical validation: Have attackers already succeeded?
THOR, Nextron’s forensic scanner, is specifically designed for this purpose. It applies thousands of YARA, SIGMA, and custom IOC rules directly on systems, either live or on forensic images. THOR identifies:
- Outputs of hacking tools (e.g., sass.dmp, pwdump.log)
- Suspicious registry changes
- Signed-but-malicious binaries
- Obfuscated web shells and renamed hacking utilities
Its forensic-first approach uncovers attacker traces that remain invisible to policy-based or behavior-only detections.
THOR and Microsoft Defender for Endpoint: A Complementary Pair
The NCSC explicitly recommended deploying Microsoft Defender for Endpoint to mitigate the SharePoint vulnerabilities. THOR integrates directly with Microsoft Defender for Endpoint’s Live Response feature, enabling on-demand scans using THOR Cloud Launcher, directly from the Defender console.
This integration allows defenders to:
- Trigger compromise scans without deploying additional infrastructure
- Collect artifacts (logs, dumps) for deeper analysis
- Confirm or disprove suspicion rapidly and with minimal operational friction
Operational Lessons from the Colt Breach
From a forensic standpoint, the Colt incident exemplifies the need for validation, even in well-governed environments. Patches, endpoint telemetry, and policies can fail silently, especially when operational procedures (e.g., patch pipelines) lag behind attacker timelines.
Recommendations:
- Validate security posture through scheduled or incident-triggered compromise assessments.
- Scan endpoints and forensic images using tools that detect what attackers leave behind, not just what they bring in.
- Use THOR to uncover traces that remain on disk long after active malware is removed or expired.
Conclusion
Security policies and detection frameworks provide essential layers of defense. But without validating outcomes, they offer a false sense of security. The breaches at Colt, M&S, and Flutter illustrate that failure to detect post-compromise artifacts is often the real gap, not the absence of policy.
If you’re not conducting compromise assessments, you’re not verifying your security posture.
See THOR in Action
Curious how THOR can help your organization uncover traces of attacker activity that traditional tools overlook?
We offer individual live demonstrations tailored to your use case – whether you’re focused on incident response, forensic validation, or large-scale compromise assessments.
Request your demo to explore how THOR fits into your detection and response strategy: Get started with Nextron Systems.
