Techniques
Sample rules
Windows AD Abnormal Object Access Activity
- source: splunk
- technicques:
- T1087
- T1087.002
Description
The following analytic identifies a statistically significant increase in access to Active Directory objects, which may indicate attacker enumeration. It leverages Windows Security Event Code 4662 to monitor and analyze access patterns, comparing them against historical averages to detect anomalies. This activity is significant for a SOC because abnormal access to AD objects can be an early indicator of reconnaissance efforts by an attacker. If confirmed malicious, this behavior could lead to unauthorized access, privilege escalation, or further compromise of the Active Directory environment.
Detection logic
`wineventlog_security` EventCode=4662
| stats min(_time) AS firstTime, max(_time) AS lastTime, dc(ObjectName) AS ObjectName_count, values(ObjectType) AS ObjectType, latest(Computer) AS dest count BY SubjectUserName
| eventstats avg(ObjectName_count) AS average stdev(ObjectName_count) AS standarddev
| eval limit = round((average+(standarddev*3)),0), user = SubjectUserName
| where ObjectName_count > limit
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_ad_abnormal_object_access_activity_filter`
Windows AD Privileged Object Access Activity
- source: splunk
- technicques:
- T1087
- T1087.002
Description
The following analytic detects access attempts to privileged Active Directory objects, such as Domain Admins or Enterprise Admins. It leverages Windows Security Event Code 4662 to identify when these sensitive objects are accessed. This activity is significant because such objects should rarely be accessed by normal users or processes, and unauthorized access attempts may indicate attacker enumeration or lateral movement within the domain. If confirmed malicious, this activity could allow attackers to escalate privileges, persist in the environment, or gain control over critical domain resources.
Detection logic
`wineventlog_security` EventCode=4662 ObjectName IN ( "CN=Account Operators,*", "CN=Administrators,*", "CN=Backup Operators,*", "CN=Cert Publishers,*", "CN=Certificate Service DCOM Access,*", "CN=Domain Admins,*", "CN=Domain Controllers,*", "CN=Enterprise Admins,*", "CN=Enterprise Read-only Domain Controllers,*", "CN=Group Policy Creator Owners,*", "CN=Incoming Forest Trust Builders,*", "CN=Microsoft Exchange Servers,*", "CN=Network Configuration Operators,*", "CN=Power Users,*", "CN=Print Operators,*", "CN=Read-only Domain Controllers,*", "CN=Replicators,*", "CN=Schema Admins,*", "CN=Server Operators,*", "CN=Exchange Trusted Subsystem,*", "CN=Exchange Windows Permission,*", "CN=Organization Management,*")
| rex field=ObjectName "CN\=(?<object_name>[^,]+)"
| stats values(Computer) as dest, values(object_name) as object_name, dc(ObjectName) as object_count, min(_time) as firstTime, max(_time) as lastTime, count by SubjectUserName
| rename SubjectUserName as user
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_ad_privileged_object_access_activity_filter`