Local Privilege Escalation With KrbRelayUp

• Windows Kerberos Local Successful Logon :
  endpoint Endpoint risk_score:64 2024-11-28 version:5
  The following analytic identifies a local successful authentication event on a Windows endpoint using the Kerberos package. It detects EventCode 4624 with LogonType 3 and source address 127.0.0.1, indicating a login to the built-in local Administrator account. This activity is significant as it may suggest a Kerberos relay attack, a method attackers use to escalate privileges. If confirmed malicious, this could allow an attacker to gain unauthorized access to sensitive systems, execute arbitrary code, or create new accounts in Active Directory, leading to potential system compromise.


• Windows Computer Account Created by Computer Account :
  endpoint Endpoint risk_score:30 2024-09-30 version:4
  The following analytic identifies a computer account creating a new computer account with a specific Service Principal Name (SPN) "RestrictedKrbHost". This detection leverages Windows Security Event Logs, specifically EventCode 4741, to identify such activities. This behavior is significant as it may indicate an attempt to establish unauthorized Kerberos authentication channels, potentially leading to lateral movement or privilege escalation. If confirmed malicious, this activity could allow an attacker to impersonate services, access sensitive information, or maintain persistence within the network.


• Windows Computer Account With SPN :
  endpoint Endpoint risk_score:64 2024-11-28 version:5
  The following analytic detects the addition of Service Principal Names (SPNs) HOST and RestrictedKrbHost to a computer account, indicative of KrbRelayUp behavior. This detection leverages Windows Security Event Logs, specifically EventCode 4741, to identify changes in SPNs. This activity is significant as it is commonly associated with Kerberos-based attacks, which can be used to escalate privileges or perform lateral movement within a network. If confirmed malicious, this behavior could allow an attacker to impersonate services, potentially leading to unauthorized access to sensitive resources.


• Windows KrbRelayUp Service Creation :
  endpoint Endpoint risk_score:64 2024-11-28 version:5
  The following analytic detects the creation of a service with the default name "KrbSCM" associated with the KrbRelayUp tool. It leverages Windows System Event Logs, specifically EventCode 7045, to identify this activity. This behavior is significant as KrbRelayUp is a known tool used for privilege escalation attacks. If confirmed malicious, this activity could allow an attacker to escalate privileges, potentially gaining unauthorized access to sensitive systems and data.


• Windows Computer Account Requesting Kerberos Ticket :
  endpoint Endpoint risk_score:35 2024-09-30 version:4
  The following analytic detects a computer account requesting a Kerberos ticket, which is unusual as typically user accounts request these tickets. This detection leverages Windows Security Event Logs, specifically EventCode 4768, to identify instances where the TargetUserName ends with a dollar sign ($), indicating a computer account. This activity is significant because it may indicate the use of tools like KrbUpRelay or other Kerberos-based attacks. If confirmed malicious, this could allow attackers to impersonate computer accounts, potentially leading to unauthorized access and lateral movement within the network.