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splunk-security_content/detections/application/windows_ad_suspicious_attribute_modification.yml
2024-10-24 14:13:05 -07:00

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YAML

name: Windows AD Suspicious Attribute Modification
id: 5682052e-ce55-4f9f-8d28-59191420b7e0
version: 2
date: '2024-09-30'
author: Dean Luxton
status: production
type: TTP
data_source:
- Windows Security 5136
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: '`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`'
how_to_implement: 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.
references:
- https://trustedsec.com/blog/a-hitchhackers-guide-to-dacl-based-detections-part-1-a
- https://lantern.splunk.com/Security/Product_Tips/Enterprise_Security/Enabling_an_audit_trail_from_Active_Directory
drilldown_searches:
- name: View the detection results for - "$src_user$" and "$dest$"
search: '%original_detection_search% | search src_user = "$src_user$" dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$src_user$" and "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src_user$", "$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
tags:
analytic_story:
- Sneaky Active Directory Persistence Tricks
asset_type: Endpoint
confidence: 100
impact: 100
message: $src_user$ has added $AttributeLDAPDisplayName$ ACL rights to $ObjectClass$ $ObjectDN$
mitre_attack_id:
- T1550
- T1222
- T1222.001
observable:
- name: src_user
type: User
role:
- Victim
- name: dest
type: Hostname
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
risk_score: 100
required_fields:
- _time
- OperationType
- ObjectDN
- OpCorrelationID
- src_user
- AttributeLDAPDisplayName
- AttributeValue
- ObjectClass
- SubjectLogonId
- DSName
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1222.001/dacl_abuse/suspicious_acl_modification-windows-security-xml.log
source: XmlWinEventLog:Security
sourcetype: xmlwineventlog