VPN login by a dormant user

Synopsis

Activation Period	14 Days
Training Period	30 Days
Test Period	N/A (single event)
Deduplication Period	1 Day
Required Data	Requires one of the following data sources: Palo Alto Networks Global Protect OR Third-Party VPNs
Detection Modules	Identity Analytics
ATT&CK Tactic	Defense Evasion (TA0005)
ATT&CK Technique	Valid Accounts: Domain Accounts (T1078.002)
Severity	Informational

A dormant user logged on to a VPN service after having been unused for a month or longer.
This may indicate the account is misused by an attacker.

Use a compromised user account which has not been used for a long while, and therefore is less likely to be noticed.

Confirm that the activity is benign (e.g. the user returned from a long leave of absence).
See whether there are other abnormal actions done by the user (e.g. files\commands\other logins).
Check if the user initiated other logins aside from a VPN login.
Check whether you have issues with your Cloud Identity Engine failing to sync data from Active Directory.