Detection rules › Splunk
Windows Steal Authentication Certificates - ESC1 Abuse
The following analytic detects when a new certificate is requested or granted against Active Directory Certificate Services (AD CS) using a Subject Alternative Name (SAN). It leverages Windows Security Event Codes 4886 and 4887 to identify these actions. This activity is significant because improperly configured certificate templates can be exploited for privilege escalation and environment compromise. If confirmed malicious, an attacker could gain elevated privileges or persist within the environment, potentially leading to unauthorized access to sensitive information and further exploitation.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1649 Steal or Forge Authentication Certificates |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Security-Auditing | 4886 | Certificate Services received a certificate request. |
| Security-Auditing | 4887 | Certificate Services approved a certificate request and issued a certificate. |
Stages and Predicates
Stage 1: search
search Attributes="*CertificateTemplate:*" Attributes="*SAN:*upn*" EventCode IN (4886, 4887)
Stage 2: stats
stats BY Computer, EventCode, Requester, Attributes, RequestId
Stage 3: search
search
Stage 4: search
search
Stage 5: fillnull
fillnull
Stage 6: rex
rex field=Attributes ...
Stage 7: rex
rex field=Attributes ...
Stage 8: rex
rex field=Attributes ...
Stage 9: rex
rex field=Attributes ...
Stage 10: rex
rex field=Requester ...
Stage 11: eval
eval ... using (Computer, EventCode, req_dest_1, req_dest_2, req_src)
Stage 12: fields
fields req_*
Stage 13: rename
rename
Stage 14: 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 |
|---|---|---|
Attributes | eq |
|
EventCode | in |
|