Hackers Exploit Free EDR Trials to Disable Active Endpoint Protections

Researchers have uncovered a sophisticated attack technique where cybercriminals exploit free trial versions of Endpoint Detection and Response (EDR) software to disable existing security defenses on compromised systems.

This approach, known as BYOEDR (Bring Your Own EDR), marks a significant advancement in defense evasion tactics, turning legitimate security tools into weapons against themselves.

Key Points

1. Threat actors leverage free EDR trials to neutralize active security tools.
2. BYOEDR is simple yet highly effective, allowing attackers to bypass protections.
3. Security teams should block unauthorized installations and enhance software validation processes.

Exploiting EDR Trial Programs

First identified by researchers Mike Manrod and Ezra Woods, this technique demonstrates how attackers can freely access trial versions of EDR products and deploy them to dismantle or disable competing security solutions already running on targeted systems.

Here’s a sharper, more concise rewrite that maintains the technical detail and professional tone:

During testing, researchers demonstrated how Cisco Secure Endpoint (AMP) can be installed and configured to disable CrowdStrike Falcon and Elastic Defend without raising alerts or generating telemetry—other than the host appearing offline.

According to Mike Manrod and Ezra Woods, the technique exploits legitimate EDR administrative features through the following steps:

1. Privilege Escalation – Attackers gain local administrator access on the target system.
2. Agent Deployment – They register for free EDR trials, download the agent installer, and deploy it.
3. Policy Manipulation – In the EDR console (Management > Policies > Protect > Windows), all exclusions are removed from the Exclusions tab.
4. Process Blocking – The SHA256 hash of the target EDR process is identified and added to the Blocked Application List (Outbreak Control > Blocked Application).

This approach is particularly dangerous because it bypasses tamper protection, enabling unauthorized modification of security software. Compared to advanced evasion methods like BYOVD (Bring Your Own Vulnerable Driver) or DLL unhooking, this BYOEDR (Bring Your Own EDR) tactic offers lower complexity but similar effectiveness.

Mitigations

This technique arises amid a surge in Remote Management and Monitoring (RMM) tool abuse, with the 2024 CrowdStrike Threat Hunting Report showing a 70% YoY increase. Malicious actors benefit from the legitimacy of EDR tools, which carry trusted certificates that lower detection chances.

Security experts recommend:

• Enforcing application control, custom IOAs (Indicators of Attack), and application-aware firewalls to block unauthorized RMM and EDR installations.
• Maintaining strong fundamentals such as network segmentation, host hardening, regular patching, and restricting local administrator privileges.

The research team further urges EDR vendors to improve trial registration validation and introduce tenant isolation safeguards to prevent agent hijacking.