Analytics BIOC Informational

Unusual hostname for the sending mail server in the email headers

The detected mail server hostname had not been observed in the organization's emails in the past 30 days.

Module:
Email Security
Licensed by:
Email Security
Data source:
Microsoft 365 Emails
ATT&CK tactics: Defense Evasion (TA0005)
ATT&CK techniques: Impersonation (T1656)
Detector tags: Spoofing
Attacker's goals:

Disguise the email's origin by spoofing the received header to appear as a trusted sender, impersonating a trusted source, aims to mislead recipients into disclosing private data or performing unsafe acts.

Investigative actions:

Review the email's received headers, to trace its path and spot spoofing signs. Examine the sender's IP address and domain reputation. Closely inspect the email content for malicious links, attachments, or requests for sensitive information. Monitor further actions taken, such as file downloads or access to potentially malicious links.

Test period:
N/A (single event)
Deduplication:
1 Day