Authentication Attempt From a Dormant Account

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	N/A (single event)
Deduplication Period	31 Days
Required Data	Requires one of the following data sources: Palo Alto Networks Firewall traffic Logs OR XDR Agent
ATT&CK Tactic	Stealth (TA0005)
ATT&CK Technique	Valid Accounts (T1078)
Severity	Informational

Description

A dormant user account tried to authenticate to a service using a TGS after having been unused for a year or more. This may indicate the account is misused by an attacker.

Attacker's Goals

Use a compromised user account that has not been used in a long time and therefore less likely to be noticed.

Investigative actions

• See whether the service authentication was successful.
• Confirm that the activity is benign (e.g. the user returned from a long leave of absence).
• Check whether you have issues with your Cloud Identity Engine failing to sync data from Active Directory.

Variations

Authentication Attempt From a Dormant Account to a sensitive server

Synopsis

Field	Value
ATT&CK Tactic	Stealth (TA0005)
ATT&CK Technique	Valid Accounts (T1078)
Severity	Low

Description

A dormant user account tried to authenticate to a service using a TGS after having been unused for a year or more. This may indicate the account is misused by an attacker on a sensitive server.

Attacker's Goals

Use a compromised user account that has not been used in a long time and therefore less likely to be noticed.

Investigative actions

• See whether the service authentication was successful.
• Confirm that the activity is benign (e.g. the user returned from a long leave of absence).
• Check whether you have issues with your Cloud Identity Engine failing to sync data from Active Directory.