ID | Technique | Tactic |
---|---|---|
T1550 | Use Alternate Authentication Material | Defense Evasion |
T1222 | File and Directory Permissions Modification | Lateral Movement |
T1222.001 | Windows File and Directory Permissions Modification | Defense Evasion |
Detection: Windows AD Suspicious Attribute Modification
Description
This detection monitors changes to the following Active Directory attributes: "msDS-AllowedToDelegateTo", "msDS-AllowedToActOnBehalfOfOtherIdentity", "msDS-KeyCredentialLink", "scriptPath", and "msTSInitialProgram". Modifications to these attributes can indicate potential malicious activity or privilege escalation attempts. Immediate investigation is recommended upon alert.
Search
1`wineventlog_security` EventCode=5136 AttributeLDAPDisplayName IN ("msDS-AllowedToDelegateTo","msDS-AllowedToActOnBehalfOfOtherIdentity","scriptPath","msTSInitialProgram") OperationType=%%14674 ```Changes to the attribute "msDS-KeyCredentialLink" are also worth moniroting, however tuning will need to be applied```
2| table _time ObjectClass ObjectDN OpCorrelationID src_user SubjectLogonId DSName AttributeValue AttributeLDAPDisplayName
3| rename SubjectLogonId as TargetLogonId, src_user as initiator, _time as eventTime
4| appendpipe [
5| map search="search `wineventlog_security` EventCode=4624 TargetLogonId=$TargetLogonId$"]
6| stats min(eventTime) as _time values(initiator) as src_user, values(DSName) as targetDomain, values(ObjectDN) as ObjectDN, values(ObjectClass) as ObjectClass, values(src_category) as src_category, values(src_ip) as src_ip values(LogonType) as LogonType values(AttributeValue) as AttributeValue values(AttributeLDAPDisplayName) as AttributeLDAPDisplayName by TargetLogonId
7| rex field=ObjectDN "^CN=(?P<cn>.*?),[A-Z]{2}\="
8| eval dest=if(ObjectClass="computer",cn,null), user=if(ObjectClass="user",cn,null)
9| fields - cn
10| `windows_ad_suspicious_attribute_modification_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|---|
wineventlog_security | eventtype=wineventlog_security OR Channel=security OR source=XmlWinEventLog:Security |
windows_ad_suspicious_attribute_modification_filter | search * |
windows_ad_suspicious_attribute_modification_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
Ensure you are ingesting Active Directory audit logs - specifically event 5136. See lantern article in references for further on how to onboard AD audit data. Ensure the wineventlog_security macro is configured with the correct indexes.
Known False Positives
If key credentials are regularly assigned to users, these events will need to be tuned out.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
$src_user$ has added $AttributeLDAPDisplayName$ ACL rights to $ObjectClass$ $ObjectDN$ | 100 | 100 | 100 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Security |
xmlwineventlog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Security |
xmlwineventlog |
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 1