⚠️ WARNING THIS IS A EXPERIMENTAL DETECTION
We have not been able to test, simulate or build datasets for it, use at your own risk!
This search can help the detection of compromised accounts or internal users sending suspcious calendar invites via GSuite calendar. These invites may contain malicious links or attachments.
- Type: Hunting
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2021-10-24
- Author: Rod Soto, Teoderick Contreras
- ID: 03cdd68a-34fb-11ec-9bd3-acde48001122
`gsuite_calendar` |bin span=5m _time |rename parameters.* as * |search target_calendar_id!=null email="*yourdomain.com" | stats count values(target_calendar_id) values(event_title) values(event_guest) by email _time | where count >100 | `gsuite_suspicious_calendar_invite_filter`
Associated Analytic Story
How To Implement
In order to successfully implement this search, you need to be ingesting logs related to gsuite (gsuitejson) having the file sharing metadata like file type, source owner, destination target user, description, etc. This search can also be made more specific by selecting specific emails, subdomains timeframe, organizational units, targeted user, etc. In order for the search to work for your environment please update
yourdomain.com value in the query with the domain relavant for your organization.
Kill Chain Phase
Known False Positives
This search will also produce normal activity statistics. Fields such as email, ip address, name, parameters.organizer_calendar_id, parameters.target_calendar_id and parameters.event_title may give away phishing intent.For more specific results use email parameter.
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