Elastic Security Detection Rules

Microsoft 365 Exchange Safe Attachment Rule Disabled

Last updated 5 months ago on 2025-01-15
Created 5 years ago on 2020-11-19

About

Identifies when a safe attachment rule is disabled in Microsoft 365. Safe attachment rules can extend malware protections to include routing all messages and attachments without a known malware signature to a special hypervisor environment. An adversary or insider threat may disable a safe attachment rule to exfiltrate data or evade defenses.
Tags
Domain: CloudData Source: Microsoft 365Use Case: Configuration AuditTactic: Defense EvasionLanguage: kuery
Severity
low
Risk Score
21
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

↳ Impair Defenses (T1562)(opens in a new tab or window)

False Positive Examples
A safe attachment rule may be disabled by a system or network administrator. Verify that the configuration change was expected. Exceptions can be added to this rule to filter expected behavior.
License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Query (Kibana Query Language)
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
filebeat-*logs-o365*
Related Integrations

o365(opens in a new tab or window)

Query
event.dataset:o365.audit and event.provider:Exchange and event.category:web and event.action:"Disable-SafeAttachmentRule" and event.outcome:success

Install detection rules in Elastic Security

Detect Microsoft 365 Exchange Safe Attachment Rule Disabled in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).