Deployment guidance for Microsoft Defender for Endpoint on Linux for SAP

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This article provides deployment guidance for Microsoft Defender for Endpoint on Linux for SAP. This article includes recommended SAP OSS (Online Services System) notes, the system requirements, prerequisites, important configuration settings, recommended antivirus exclusions, and guidance on scheduling antivirus scans.

Conventional security defenses that have been commonly used to protect SAP systems, such as isolating infrastructure behind firewalls and limiting interactive operating system logons, are no longer considered sufficient to mitigate modern sophisticated threats. It's essential to deploy modern defenses to detect and contain threats in real-time. SAP applications unlike most other workloads require basic assessment and validation before deploying Microsoft Defender for Endpoint. The enterprise security administrators should contact the SAP Basis team prior to deploying Defender for Endpoint. The SAP Basis Team should be cross trained with a basic level of knowledge about Defender for Endpoint.

SAP Applications on Linux

  • SAP only supports Suse, Redhat, and Oracle Linux. Other distributions aren't supported for SAP S4 or NetWeaver applications.
  • Suse 15.x, Redhat 8.x or 9.x and Oracle Linux 8.x are strongly recommended.
  • Suse 12.x, Redhat 7.x and Oracle Linux 7.x are technically supported but weren't extensively tested.
  • Suse 11.x, Redhat 6.x and Oracle Linux 6.x might not be supported and weren't tested.
  • Suse and Redhat offer tailored distributions for SAP. These "for SAP" versions of Suse and Redhat might have different packages preinstalled and possibly different kernels.
  • SAP only supports certain Linux File systems. In general, XFS and EXT3 are used. Oracle Automatic Storage Management (ASM) filesystem is sometimes used for Oracle DBMS and can't be read by Defender for Endpoint.
  • Some SAP applications use "standalone engines" such as TREX, Adobe Document Server, Content Server and LiveCache. These engines require specific configuration and file exclusions.
  • SAP applications often have Transport and Interface directories with many thousands of small files. If the number of files is larger than 100,000, it might and affect performance. It's recommended to archive files.
  • It's strongly recommended to deploy Defender for Endpoint to nonproductive SAP landscapes for several weeks before deploying to production. The SAP Basis Team should use tools such as sysstat, KSAR, and nmon to verify if CPU and other performance parameters are impacted.

Prerequisites for deploying Microsoft Defender for Endpoint on Linux on SAP VMs

  • Microsoft Defender for Endpoint version >= 101.23082.0009 | Release version: 30.123082.0009 or higher must be deployed.
  • Microsoft Defender for Endpoint on Linux supports all the Linux releases used by SAP applications.
  • Microsoft Defender for Endpoint on Linux requires connectivity to specific Internet endpoints from VMs to update antivirus Definitions.
  • Microsoft Defender for Endpoint on Linux requires some crontab (or other task scheduler) entries to schedule scans, log rotation, and Microsoft Defender for Endpoint updates. Enterprise Security teams normally manage these entries. Refer to How to schedule an update of the Microsoft Defender for Endpoint (Linux).

The default configuration option for deployment as an Azure Extension for AntiVirus (AV) is Passive Mode. This means that Microsoft Defender Antivirus, the AV component of Microsoft Defender for Endpoint, doesn't intercept IO calls. It's recommended to run Microsoft Defender for Endpoint in Passive Mode on all SAP applications and to schedule a scan once per day. In this mode:

  • Real-time protection is turned off: Threats aren't remediated by Microsoft Defender Antivirus.
  • On-demand scanning is turned on: Still use the scan capabilities on the endpoint.
  • Automatic threat remediation is turned off: No files are moved and the security administrator is expected to take required action.
  • Security intelligence updates are turned on: Alerts are available on security administrator's tenant.

Online Kernel patching tools such as Ksplice or similar can lead to unpredictable OS stability if Defender for Endpoint is running. It is recommended to temporarily stop the Defender for Endpoint daemon prior to performing online Kernel patching. After the Kernel is updated Defender for Endpoint on Linux can be safely restarted. This is especially important on large SAP HANA VMs with huge memory contexts.

The Linux crontab is typically used to schedule Microsoft Defender for Endpoint AV scan and log rotation tasks: How to schedule scans with Microsoft Defender for Endpoint (Linux)

Endpoint Detection and Response (EDR) functionality is active whenever Microsoft Defender for Endpoint on Linux is installed. There's no simple way to disable EDR functionality through command line or configuration. For more information on troubleshooting EDR, see the sections Useful Commands and Useful Links.

Important Configuration Settings for Microsoft Defender for Endpoint on SAP on Linux

It's recommended to check the installation and configuration of Defender for Endpoint with the command mdatp health.

The key parameters recommended for SAP applications are:

  • healthy = true
  • release_ring = Production. Prerelease and insider rings shouldn't be used with SAP Applications.
  • real_time_protection_enabled = false. Real-time protection is off in passive mode, which is the default mode and prevents real-time IO interception.
  • automatic_definition_update_enabled = true
  • definition_status = "up_to_date". Run a manual update if a new value is identified.
  • edr_early_preview_enabled = "disabled". If enabled on SAP systems it might lead to system instability.
  • conflicting_applications = [ ]. Other AV or security software installed on a VM such as Clam.
  • supplementary_events_subsystem = "ebpf". Don't proceed if ebpf isn't displayed. Contact the security admin team.

This article has some useful hints on troubleshooting installation issues for Microsoft Defender for Endpoint: Troubleshoot installation issues for Microsoft Defender for Endpoint on Linux

Enterprise Security Team must obtain a full list of antivirus exclusions from the SAP Administrators (typically the SAP Basis Team). It's recommended to initially exclude:

Oracle ASM systems don't need exclusions as Microsoft Defender for Endpoint can't read ASM disks.

Customers with Pacemaker clusters should also configure these exclusions:

mdatp exclusion folder add --path /usr/lib/pacemaker/  (for RedHat /var/lib/pacemaker/)

mdatp exclusion process add --name pacemakerd

mdatp exclusion process add --name crm_*

Customers running the Azure Security security policy might trigger a scan using the Freeware Clam AV solution. It's recommended to disable Clam AV scan after a VM has been protected with Microsoft Defender for Endpoint using following commands:

sudo azsecd config  -s clamav -d "Disabled"

sudo service azsecd restart

sudo azsecd status

The following articles detail how to configure AV exclusions for processes, files, and folders per individual VM:

Scheduling a Daily AV Scan

The recommended configuration for SAP applications disables real-time interception of IO calls for AV scanning. The recommended setting is passive mode in which real_time_protection_enabled = false.

The following link details how to schedule a scan: How to schedule scans with Microsoft Defender for Endpoint (Linux).

Large SAP systems might have more than 20 SAP application servers each with a connection to the SAPMNT NFS share. Twenty or more application servers simultaneously scanning the same NFS server will likely overload the NFS server. By default, Defender for Endpoint on Linux doesn't scan NFS sources.

If there's a requirement to scan SAPMNT then this scan should be configured on one or two VMs only.

Scheduled scans for SAP ECC, BW, CRM, SCM, Solution Manager, and other components should be staggered at different times to avoid all SAP components from overloading a shared NFS storage source shared by all SAP components.

Useful Commands

If, during manual zypper installation on Suse an error "Nothing provides 'policycoreutils'" occurs, refer to: Troubleshoot installation issues for Microsoft Defender for Endpoint on Linux.

There are several command-line commands that can control the operation of mdatp. To enable passive mode, you can use the following command:

mdatp config passive-mode --value enabled

Note

passive mode is the default mode on installing defender for endpoint on Linux.

To turn off real-time protection, you can use the command:

mdatp config real-time-protection --value disabled

This command tells mdatp to retrieve the latest definitions from the cloud:

mdatp definitions update

This command tests whether mdatp can connect to the cloud-based endpoints via the network:

mdatp connectivity test

These commands update the mdatp software, if needed:

yum update mdatp

zypper update mdatp

Since mdatp runs as a linux system service, you can control mdatp using the service command, for example:

service mdatp status

This command creates a diagnostic file that can be uploaded to Microsoft support:

sudo mdatp diagnostic create