Analytics BIOC Medium

Mailbox Client Access Setting (CAS) changed

An attacker may use PowerShell to change the Client Access Settings (CAS) for a mailbox, hence gaining access to the data.

Module:
Platform Analytics
Data source:
Windows Event Collector, XDR Agent with eXtended Threat Hunting (XTH)
ATT&CK tactics: Collection (TA0009)
ATT&CK techniques: Data Staged: Local Data Staging (T1074.001)
Attacker's goals:

Gain access to the data in the compromised mailbox.

Investigative actions:

Examine the PowerShell command to identify which mailbox's access setting has been modified. Verify that the change in the client access setting was executed by a trusted source.

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