Important
The exclusions described in this article don’t apply to other Defender for Endpoint on Linux capabilities, including endpoint detection and response (EDR). Files that you exclude using the methods described in this article can still trigger EDR alerts and other detections.
You can exclude certain files, folders, processes, and process-opened files from Defender for Endpoint on Linux scans.
Exclusions can be useful to avoid incorrect detections on files or software that are unique or customized to your organization. They can also be useful for mitigating performance issues caused by Defender for Endpoint on Linux.
Warning
Defining exclusions lowers the protection offered by Defender for Endpoint on Linux. You should always evaluate the risks that are associated with implementing exclusions, and you should only exclude files that you are confident are not malicious.
Supported exclusion types
The follow table shows the exclusion types supported by Defender for Endpoint on Linux.
| Exclusion | Definition | Examples |
|---|---|---|
| File extension | All files with the extension, anywhere on the device | .test |
| File | A specific file identified by the full path | /var/log/test.log/var/log/*.log/var/log/install.?.log |
| Folder | All files under the specified folder (recursively) | /var/log//var/*/ |
| Process | A specific process (specified either by the full path or file name) and all files opened by it | /bin/catcatc?t |
Important
The paths above must be hard links, not symbolic links, in order to be successfully excluded. You can check if a path is a symbolic link by running file <path-name>.
File, folder, and process exclusions support the following wildcards:
| Wildcard | Description | Example | Matches | Does not match |
|---|---|---|---|---|
| * | Matches any number of any characters including none (note that when this wildcard is used inside a path it will substitute only one folder) | /var/\*/\*.log |
/var/log/system.log |
/var/log/nested/system.log |
| ? | Matches any single character | file?.log |
file1.logfile2.log |
file123.log |
How to configure the list of exclusions
From the management console
For more information on how to configure exclusions from Puppet, Ansible, or another management console, see Set preferences for Defender for Endpoint on Linux.
From the command line
Run the following command to see the available switches for managing exclusions:
mdatp exclusion
Tip
When configuring exclusions with wildcards, enclose the parameter in double-quotes to prevent globbing.
Examples:
- Add an exclusion for a file extension:
Bash
mdatp exclusion extension add --name .txtOutputExtension exclusion configured successfully - Add an exclusion for a file:
Bash
mdatp exclusion file add --path /var/log/dummy.logOutputFile exclusion configured successfully - Add an exclusion for a folder:
Bash
mdatp exclusion folder add --path /var/log/OutputFolder exclusion configured successfully - Add an exclusion for a second folder:
Bash
mdatp exclusion folder add --path /var/log/ mdatp exclusion folder add --path /other/folderOutputFolder exclusion configured successfully - Add an exclusion for a folder with a wildcard in it:
Bash
mdatp exclusion folder add --path "/var/*/"Note
This will only exclude paths one level below /var/, but not folders which are more deeply nested; for example, /var/this-subfolder/but-not-this-subfolder.
Bashmdatp exclusion folder add --path "/var/"Note
This will exclude all paths whose parent is /var/; for example, /var/this-subfolder/and-this-subfolder-as-well.
OutputFolder exclusion configured successfully - Add an exclusion for a process:
Bash
mdatp exclusion process add --name catOutputProcess exclusion configured successfully - Add an exclusion for a second process:
Bash
mdatp exclusion process add --name cat mdatp exclusion process add --name dogOutputProcess exclusion configured successfully
Validate exclusions lists with the EICAR test file
You can validate that your exclusion lists are working by using curl to download a test file.
In the following Bash snippet, replace test.txt with a file that conforms to your exclusion rules. For example, if you have excluded the .testing extension, replace test.txt with test.testing. If you are testing a path, ensure that you run the command within that path.
curl -o test.txt https://www.eicar.org/download/eicar.com.txt
If Defender for Endpoint on Linux reports malware, then the rule is not working. If there is no report of malware, and the downloaded file exists, then the exclusion is working. You can open the file to confirm that the contents are the same as what is described on the EICAR test file website.
If you do not have Internet access, you can create your own EICAR test file. Write the EICAR string to a new text file with the following Bash command:
echo 'X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*' > test.txt
You can also copy the string into a blank text file and attempt to save it with the file name or in the folder you are attempting to exclude.
Allow threats
In addition to excluding certain content from being scanned, you can also configure the product not to detect some classes of threats (identified by the threat name). You should exercise caution when using this functionality, as it can leave your device unprotected.
To add a threat name to the allowed list, execute the following command:
mdatp threat allowed add --name [threat-name]
The threat name associated with a detection on your device can be obtained using the following command:
mdatp threat list
For example, to add EICAR-Test-File (not a virus) (the threat name associated with the EICAR detection) to the allowed list, execute the following command:
mdatp threat allowed add --name "EICAR-Test-File (not a virus)"