This search detects when an admin configured a forwarding rule for multiple mailboxes to the same destination.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2020-12-16
- Author: Patrick Bareiss, Splunk
- ID: 7f398cfb-918d-41f4-8db8-2e2474e02c28
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 8 9 `o365_management_activity` Operation=Set-Mailbox | spath input=Parameters | rename Identity AS src_user | search ForwardingAddress=* | stats dc(src_user) AS count_src_user earliest(_time) as firstTime latest(_time) as lastTime values(src_user) AS src_user values(user) AS user by ForwardingAddress | where count_src_user > 1 |`security_content_ctime(firstTime)` |`security_content_ctime(lastTime)` |`o365_suspicious_admin_email_forwarding_filter`
The SPL above uses the following Macros:
o365_suspicious_admin_email_forwarding_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
You must install splunk Microsoft Office 365 add-on. This search works with o365:management:activity
Known False Positives
Associated Analytic Story
|48.0||80||60||User $user$ has configured a forwarding rule for multiple mailboxes to the same destination $ForwardingAddress$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1