Detection rules › Splunk
Windows Computer Account With SPN
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1558 Steal or Forge Kerberos Tickets |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Security-Auditing | 4741 | A computer account was created. |
Stages and Predicates
Stage 1: search
search EventCode=4741 NewUacValue="0x80" ServicePrincipalNames IN ("*HOST/*", "*RestrictedKrbHost/*")
Stage 2: stats
stats BY dest, Logon_ID, subject
Stage 3: search
search
Stage 4: search
search
Stage 5: search
search `macro`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
NewUacValue | eq |
|
ServicePrincipalNames | in |
|