Numerous emails sent by a single sender to multiple internal recipients

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	10 Minutes
Deduplication Period	1 Day
Required Data	Microsoft 365 Emails
Detection Modules	Email
Detector Tags	Phishing, Spam
ATT&CK Tactic	Initial Access (TA0001)
ATT&CK Technique	Phishing (T1566)
Severity	Informational

Description

Numerous emails were sent to multiple internal recipients. This may indicate spam or any other malicious attempt.

Attacker's Goals

Trick the user into clicking a link, while avoiding detection.

Investigative actions

• Examine the sender's IP address and reputation.
• Verify whether the sender's IP address has appeared in different log sources before, and if it is recognizable.
• If the message contains attachments or links, scrutinize them for any suspicious indications.
• Monitor further actions taken, such as file downloads or access to potentially malicious links.