Jonhnathan
85b72256c2
* Potential Shadow Credentials added to AD Object Initial Rule * Apply suggestions from code review Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com> * Update credential_access_shadow_credentials.toml * Add AD tag * Update credential_access_shadow_credentials.toml Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>
77 lines
2.6 KiB
TOML
77 lines
2.6 KiB
TOML
[metadata]
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creation_date = "2022/01/26"
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maturity = "production"
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updated_date = "2022/01/31"
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[rule]
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author = ["Elastic"]
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description = """
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Identify the modification of the msDS-KeyCredentialLink attribute in an Active Directory Computer or User Object.
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Attackers can abuse control over the object and create a key pair, append to raw public key in the attribute, and obtain
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persistent and stealthy access to the target user or computer object.
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"""
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false_positives = [
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"""
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Modifications in the msDS-KeyCredentialLink attribute can be done legitimately by the Azure AD Connect
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synchronization account or the ADFS service account. These accounts can be added as Exceptions.
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""",
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]
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from = "now-9m"
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index = ["winlogbeat-*", "logs-windows.*", "logs-system.*"]
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language = "kuery"
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license = "Elastic License v2"
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name = "Potential Shadow Credentials added to AD Object"
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note = """## Config
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The 'Audit Directory Service Changes' logging policy must be configured for (Success, Failure).
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Steps to implement the logging policy with Advanced Audit Configuration:
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```
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Computer Configuration >
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Policies >
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Windows Settings >
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Security Settings >
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Advanced Audit Policies Configuration >
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Audit Policies >
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DS Access >
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Audit Directory Service Changes (Success,Failure)
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```
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The above policy does not cover User objects, so we need to set up an AuditRule using https://github.com/OTRF/Set-AuditRule.
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As this specifies the msDS-KeyCredentialLink Attribute GUID, it is expected to be low noise.
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```
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Set-AuditRule -AdObjectPath 'AD:\\CN=Users,DC=Domain,DC=com' -WellKnownSidType WorldSid -Rights WriteProperty -InheritanceFlags Children -AttributeGUID 5b47d60f-6090-40b2-9f37-2a4de88f3063 -AuditFlags Success
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```
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"""
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references = [
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"https://posts.specterops.io/shadow-credentials-abusing-key-trust-account-mapping-for-takeover-8ee1a53566ab",
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"https://www.thehacker.recipes/ad/movement/kerberos/shadow-credentials",
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"https://github.com/OTRF/Set-AuditRule",
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]
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risk_score = 73
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rule_id = "79f97b31-480e-4e63-a7f4-ede42bf2c6de"
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severity = "high"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Credential Access", "Active Directory"]
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timestamp_override = "event.ingested"
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type = "query"
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query = '''
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event.action:"Directory Service Changes" and event.code:"5136" and winlog.event_data.AttributeLDAPDisplayName:"msDS-KeyCredentialLink"
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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name = "Modify Authentication Process"
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id = "T1556"
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reference = "https://attack.mitre.org/techniques/T1556/"
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[rule.threat.tactic]
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name = "Credential Access"
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id = "TA0006"
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reference = "https://attack.mitre.org/tactics/TA0006/"
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