title: Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network
id: 5588576c-5898-4fac-bcdd-7475a60e8f43
related:
    - id: b07e58cf-cacc-4135-8473-ccb2eba63dd2 # Potential Kerberos Coercion via DNS Object Spoofing
      type: similar
    - id: e7a21b5f-d8c4-4ae5-b8d9-93c5d3f28e1c # Suspicious DNS Query Indicating Kerberos Coercion via DNS Object Spoofing
      type: similar
status: experimental
description: |
    Detects DNS queries containing patterns associated with Kerberos coercion attacks via DNS object spoofing.
    The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure.
    Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts.
    It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records
    to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.
references:
    - https://www.synacktiv.com/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025
    - https://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-06-20
tags:
    - attack.collection
    - attack.credential-access
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1557.001
    - attack.t1187
logsource:
    product: zeek
    service: dns
detection:
    selection:
        query|contains|all:
            - 'UWhRCA' # Follows this pattern UWhRCAAAAA..BAAA
            - 'BAAAA'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing
id: e7a21b5f-d8c4-4ae5-b8d9-93c5d3f28e1c
related:
    - id: b07e58cf-cacc-4135-8473-ccb2eba63dd2 # Potential Kerberos Coercion via DNS Object Spoofing
      type: similar
    - id: 5588576c-5898-4fac-bcdd-7475a60e8f43 # Suspicious DNS Query Indicating Kerberos Coercion via DNS Object Spoofing - Network
      type: similar
status: experimental
description: |
    Detects DNS queries containing patterns associated with Kerberos coercion attacks via DNS object spoofing.
    The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure.
    Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts.
    It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records
    to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.
references:
    - https://www.synacktiv.com/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025
    - https://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-06-20
tags:
    - attack.collection
    - attack.credential-access
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1557.001
    - attack.t1187
logsource:
    product: windows
    category: dns_query
detection:
    selection:
        QueryName|contains|all:
            - 'UWhRCA'
            - 'BAAAA'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Attempts of Kerberos Coercion Via DNS SPN Spoofing
id: 0ed99dda-6a35-11ef-8c99-0242ac120002
related:
    - id: b07e58cf-cacc-4135-8473-ccb2eba63dd2
      type: similar
status: experimental
description: |
    Detects the presence of "UWhRC....AAYBAAAA" pattern in command line.
    The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure.
    Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts.
    It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records
    to spoof Service Principal Names (SPNs) and redirect authentication requests like in CVE-2025-33073.
    If you see this pattern in the command line, it is likely an attempt to add spoofed Service Principal Names (SPNs) to DNS records,
    or checking for the presence of such records through the `nslookup` command.
references:
    - https://www.synacktiv.com/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025
    - https://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-06-20
tags:
    - attack.collection
    - attack.credential-access
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1557.001
    - attack.t1187
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - 'UWhRCA'
            - 'BAAAA'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Potential Kerberos Coercion by Spoofing SPNs via DNS Manipulation
id: b07e58cf-cacc-4135-8473-ccb2eba63dd2
related:
    - id: e7a21b5f-d8c4-4ae5-b8d9-93c5d3f28e1c # Suspicious DNS Query Indicating Kerberos Coercion via DNS Object Spoofing
      type: similar
    - id: 5588576c-5898-4fac-bcdd-7475a60e8f43 # Suspicious DNS Query Indicating Kerberos Coercion via DNS Object Spoofing - Network
      type: similar
    - id: 0ed99dda-6a35-11ef-8c99-0242ac120002 # Kerberos Coercion Via DNS SPN Spoofing Attempt
      type: similar
status: experimental
description: |
    Detects modifications to DNS records in Active Directory where the Distinguished Name (DN) contains a base64-encoded blob
    matching the pattern "1UWhRCAAAAA...BAAAA". This pattern corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure,
    commonly used in Kerberos coercion attacks. Adversaries may exploit this to coerce victim systems into authenticating to
    attacker-controlled hosts by spoofing SPNs via DNS. It is one of the strong indicators of a Kerberos coercion attack,.
    where adversaries manipulate DNS records to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.
    Please investigate the user account that made the changes, as it is likely a low-privileged account that has been compromised.
references:
    - https://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html
    - https://www.synacktiv.com/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-06-20
tags:
    - attack.collection
    - attack.credential-access
    - attack.t1557.003
    - attack.persistence
    - attack.privilege-escalation
logsource:
    product: windows
    service: security
    definition: |
      By default these events are not logged by default for MicrosoftDNS objects in Active Directory.
      To enable detection, configure an AuditRule on the DNS object container with the "CreateChild" permission for the "Everyone" principal.
      This can be accomplished using tools such as Set-AuditRule (see https://github.com/OTRF/Set-AuditRule).
detection:
    selection_directory_service_changes:
        EventID:
            - 5136
            - 5137
        ObjectClass: 'dnsNode'
        ObjectDN|contains|all: # ObjectDN">DC=foo-11UWhRCAAAAAAAAAAAAAAAAAAAAAAAAAAAAwbEAYBAAAA,DC=domain.com,CN=MicrosoftDNS,DC=DomainDnsZones,DC=domain,DC=com</Data>
            - 'UWhRCA'
            - 'BAAAA'
            - 'CN=MicrosoftDNS'
    selection_directory_service_access:
        EventID: 4662
        AdditionalInfo|contains|all: # AdditionalInfo">DC=foo-11UWhRCAAAAAAAAAAAAAAAAAAAAAAAAAAAAwbEAYBAAAA,DC=domain.com,CN=MicrosoftDNS,DC=DomainDnsZones,DC=domain,DC=com</Data>
            - 'UWhRCA'
            - 'BAAAA'
            - 'CN=MicrosoftDNS'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: high