Detectionhighexperimental

Attempts of Kerberos Coercion Via DNS SPN Spoofing

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.

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Launch
Swachchhanda Shrawan Poudel (Nextron Systems)Created Fri Jun 200ed99dda-6a35-11ef-8c99-0242ac120002windows
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        CommandLine|contains|all:
            - 'UWhRCA'
            - 'BAAAA'
    condition: selection
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
0ed99dda-6a35-11ef-8c99-0242ac120002
Status
experimental
Level
high
Type
Detection
Created
Fri Jun 20
Path
rules/windows/process_creation/proc_creation_win_kerberos_coercion_via_dns_spn_spoofing.yml
Raw Tags
attack.collectionattack.credential-accessattack.persistenceattack.privilege-escalationattack.t1557.001attack.t1187
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