LoFP LoFP / if key credentials are regularly assigned to users, these events will need to be tuned out.

Techniques

Sample rules

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.

Detection logic

`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``` 
| table _time ObjectClass ObjectDN OpCorrelationID src_user SubjectLogonId DSName AttributeValue AttributeLDAPDisplayName  
| rename SubjectLogonId as TargetLogonId, src_user as initiator, _time as eventTime  
| appendpipe [
| map search="search `wineventlog_security` EventCode=4624 TargetLogonId=$TargetLogonId$"]  
| 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  
| rex field=ObjectDN "^CN=(?P<cn>.*?),[A-Z]{2}\="  
| eval dest=if(ObjectClass="computer",cn,null), user=if(ObjectClass="user",cn,null) 
| fields - cn 
| `windows_ad_suspicious_attribute_modification_filter`