Sensitive Exchange mail sent to external users

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	1 Hour
Deduplication Period	1 Day
Required Data	Office 365 Audit
Detection Modules	Identity Threat Module, SaaS Threat Detection, Email
Detector Tags	O365 DLP Analytics
ATT&CK Tactic	Collection (TA0009), Exfiltration (TA0010)
ATT&CK Technique	Email Collection (T1114), Exfiltration Over Alternative Protocol (T1048)
Severity	Informational

Description

A user sent sensitive email messages to external users.

Attacker's Goals

An attacker is attempting to collect sensitive email information.

Investigative actions

• Look for signs that the user account and mailboxes are compromised (e.g. abnormal logins, unusual activity).
• Follow further actions done by the account.
• Look for unusual email patterns from the affected mailbox (e.g. unusual email contents).
• Examine the user's email activity history for suspicious behavior.

Variations

Exchange mail to external account matching high severity DLP rules

Synopsis

Field	Value
ATT&CK Tactic	Collection (TA0009), Exfiltration (TA0010)
ATT&CK Technique	Email Collection (T1114), Exfiltration Over Alternative Protocol (T1048)
Severity	Low

Description

A user sent sensitive email messages to external users.

Attacker's Goals

An attacker is attempting to collect sensitive email information.

Investigative actions

• Look for signs that the user account and mailboxes are compromised (e.g. abnormal logins, unusual activity).
• Follow further actions done by the account.
• Look for unusual email patterns from the affected mailbox (e.g. unusual email contents).
• Examine the user's email activity history for suspicious behavior.

Sensitive Exchange mail sent to an external user

Synopsis

Field	Value
ATT&CK Tactic	Collection (TA0009), Exfiltration (TA0010)
ATT&CK Technique	Email Collection (T1114), Exfiltration Over Alternative Protocol (T1048)
Severity	Low

Description

A user sent sensitive email messages to external users.

Attacker's Goals

An attacker is attempting to collect sensitive email information.

Investigative actions

• Look for signs that the user account and mailboxes are compromised (e.g. abnormal logins, unusual activity).
• Follow further actions done by the account.
• Look for unusual email patterns from the affected mailbox (e.g. unusual email contents).
• Examine the user's email activity history for suspicious behavior.