Microsoft Defender for Endpoint (MDE) must enable Tamper protection.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-275983	SRG-APP-000279	MSDE-00-000700	SV-275983r1119713_rule	2025-07-15	1

Description
Malicious code protection mechanisms include, but are not limited to, antivirus and malware detection software. To minimize potential negative impact to the organization that can be caused by malicious code, it is imperative that malicious code is identified and eradicated. Tamper protection prevents malicious apps from turning off security features like virus and threat protection, behavior monitoring, cloud-delivered protection, etc., preventing unwanted changes to security solutions and essential functions.

Description

Malicious code protection mechanisms include, but are not limited to, antivirus and malware detection software. To minimize potential negative impact to the organization that can be caused by malicious code, it is imperative that malicious code is identified and eradicated. Tamper protection prevents malicious apps from turning off security features like virus and threat protection, behavior monitoring, cloud-delivered protection, etc., preventing unwanted changes to security solutions and essential functions.

ℹ️ Check
Access the MDE portal as a user with at least an MDE Administrator or equivalent role: 1. In the navigation pane, select Settings >> Endpoints >> Advanced features (under General). 2. Verify the slide bar for "Tamper protection" is set to "On". If the slide bar for "Tamper protection" is not set to "On", this is a finding.

✔️ Fix
Access the MDE portal as a user with at least an MDE Administrator or equivalent role: 1. In the navigation pane, select Settings >> Endpoints >> Advanced features (under General). 2. Set the slide bar for "Tamper protection" to "On".