Exchange malware filter policy removed

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	N/A (single event)
Deduplication Period	1 Day
Required Data	Office 365 Audit
Detection Modules	Identity Threat Module, SaaS Threat Detection, Email
ATT&CK Tactic	Defense Impairment (TA0112)
ATT&CK Technique	Disable or Modify Tools (T1685)
Severity	Low

Description

A user removed an Exchange malware filter policy, which may prevent the detection of malware.

Attacker's Goals

An attacker is attempting to evade detection.

Investigative actions

• Follow further actions done by the account.
• Verify that the configuration change was expected.
• Look for signs that the user account is compromised (e.g. abnormal logins, unusual activity).
• Investigate if any other security policies have been changed or removed.
• Monitor for signs of malware in future messages.