On an online reference machine (same OS version):
After a Microsoft Patch Tuesday, a Windows kernel update may change the filter manager structure. If the Trend Micro driver (tmebc.sys, tmcomm.sys) was compiled for an older kernel version, it will fail to load. The agent shows as "online," but the anti-malware driver remains offline.
If using agentless anti-malware and the driver is "offline" for all VMs on a host:
The most definitive way to diagnose the failure is to review the agent logs on the endpoint.
Open regedit and navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\tmcomm
Ensure the Start DWORD value is 0 (Boot start). If it is 3 (Manual) or 4 (Disabled), change to 0 and reboot.
Check Windows Services
Check Device Manager
Review Windows Event Logs
The anti-malware driver relies on the hypervisor’s file system filter. If VMware Tools is not installed or is severely outdated, the driver cannot be injected. In Hyper-V environments, the Linux Integration Services (LIS) or Windows Integration Components may be missing.
The "Anti-Malware Driver Offline Not Installed" error is primarily a compilation or loading issue on the host side. By verifying kernel header dependencies, checking Secure Boot status, and utilizing DSM for pre-compiled driver delivery, administrators can quickly restore protection to the endpoint.
Troubleshooting Trend Micro Deep Security: Fixing the "Anti-Malware Driver Offline/Not Installed" Error
If you are managing servers with Trend Micro Deep Security, seeing the status "Anti-Malware Driver Offline / Not Installed" can be frustrating. This error indicates that the Deep Security Agent (DSA) cannot communicate with or initialize the core anti-malware drivers, leaving your workload vulnerable. Why is the Driver Showing as Offline?
Commonly, this issue occurs on Windows machines when the installation is corrupted or a critical service fails to start. Key reasons include:
Missing Root Certificates: The Windows OS may lack the necessary CA certificates to verify the driver’s digital signature, preventing installation. On an online reference machine (same OS version):
Secure Boot Issues: On Linux or newer Windows servers, if Secure Boot is enabled and the Trend Micro public key isn't enrolled, the driver will be blocked.
Software Conflicts: Other antivirus products like OfficeScan, Apex One, or ServerProtect can prevent the DSA driver from loading.
Comodo Certificate Issues: A specific known conflict with Comodo certificates can trigger this "offline" status. Step-by-Step Troubleshooting Guide 1. Initial Verification
Before performing a full reinstall, check if the necessary services are running:
Trend Micro Deep Security Agent and Trend Micro Solution Platform services should be "Running".
Run the following commands in an elevated command prompt to check driver status: sc query AMSP sc query tmcomm sc query tmactmon sc query tmevtmgr
If any of these are stopped, try restarting the Trend Micro Deep Security Agent service. 2. Resolving Secure Boot Conflicts After a Microsoft Patch Tuesday, a Windows kernel
If you have Secure Boot enabled, you must enroll the Trend Micro public key. Alternatively, you can temporarily disable Secure Boot to confirm if it is the cause of the offline status. 3. Fixing Certificate & Signature Issues
If the server is not regularly updated, it may fail to verify the driver's signature:
Apply the latest Microsoft Windows Updates to ensure root certificates are current.
If a Comodo certificate is causing the issue, you may need to manually delete specific driver files like tbimdsa.sys and tmcomm.sys before reinstalling. 4. The Clean Reinstallation (Recommended Fix)
Most "corrupted installation" cases are best solved by a clean wipe and fresh install:
Anti-Malware: Driver offline / Not installed - Deep Security
Here’s a detailed technical analysis of the scenario where the Trend Micro Deep Security Anti-Malware driver is not installed in an offline environment. checking Secure Boot status