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Splunk Enterprise Security added a detection for Windows built-in account renaming, using Security Event ID 4781 to identify changes affecting reserved relative identifiers (RIDs) 500 through 504: Administrator, Guest, krbtgt, DefaultAccount, and WDAGUtilityAccount. The analytic is disabled by default and generates a notable event with a risk score of 50 when triggered.
Renaming the RID-500 Administrator account can let an intruder retain administrative privileges while evading detections that depend on the account’s default name. The behavior maps to MITRE ATT&CK T1036.010 (Masquerade Account Name) and T1078.003 (Valid Accounts: Local Accounts), techniques used to make malicious accounts appear legitimate and abuse local credentials for persistence, remote access, and lateral movement.
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Splunk updated its "Windows Builtin Account Name Was Changed" Enterprise Security detection, which monitors Windows Security Event ID 4781 for renaming reserved built-in account SIDs with RIDs 500 through 504. The analytic is mapped to ATT&CK T1036.010 and T1078.003 and is disabled by default.
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Splunk removed several Windows-focused detections from its Threat Research content library and Enterprise Security workflows, citing renamed analytics, overly broad logic, excessive noise, or reduced effectiveness against current attacker tradecraft. The retired content covered **local administrator account creation** with `net.exe`, **domain and local account discovery**, **domain and privileged group enumeration**, **Excel spawning PowerShell**, **Mimikatz-related credential dumping**, and an **Investigation** for pass-the-hash activity based on Windows Event ID `4624` with `Logon_Type 9`. Splunk said most of the detections were removed in content library version `5.2.0`, while the pass-the-hash investigation was dropped because Enterprise Security `8.0` no longer supports Investigations. The affected detections mapped to common ATT&CK behaviors including `T1136.001` (local account creation), `T1087.001` and `T1087.002` (account discovery), `T1069.002` (domain group discovery), `T1003.001` (LSASS memory), and pass-the-hash activity involving dumped **NTLM** credentials. The changes reflect the difficulty of reliably detecting Windows credential access and reconnaissance techniques that remain widely used by threat actors, including **SAM** hive dumping (`T1003.002`) with tools such as **Mimikatz**, **Impacket/SecretsDump**, **CrackMapExec**, and **Cobalt Strike**, as documented by MITRE ATT&CK. Splunk directed users to newer replacements such as **Windows Create Local Administrator Account Via Net**, **Windows User Discovery Via Net**, **Windows Group Discovery Via Net**, **Windows Sensitive Group Discovery With Net**, and **Windows Office Product Spawned Uncommon Process**.
Aug 12, 2026
Splunk has removed its deprecated **"Network Connection Discovery With Net"** analytic and replaced it with **"Windows Network Connection Discovery Via Net"**, updating the detection logic for suspicious use of `net.exe` and `net1.exe` on Windows systems. The analytic is designed to surface command-line activity associated with **MITRE ATT&CK `T1049`**, which covers adversary reconnaissance of active network connections, open ports, sessions, and reachable resources after initial compromise. MITRE documents `T1049` as a common post-compromise behavior used by APT groups, ransomware operators, and malware families to map local network connectivity through utilities such as `netstat`, `net use`, and `net session`, as well as Windows networking APIs. Splunk said the detection relies on telemetry including **Sysmon Event ID 1**, **Windows Security Event ID 4688**, and **CrowdStrike ProcessRollup2** normalized into the Splunk Endpoint data model, and noted that while the activity can indicate reconnaissance supporting lateral movement or data exfiltration, administrators may also trigger it during legitimate troubleshooting.
Aug 12, 2026
Splunk has removed two Windows discovery analytics from its Threat Research content library and replaced them with updated detections for attacker use of built-in `net` commands to enumerate users and groups. The deprecated rules, **Local Account Discovery with Net** and **Net Localgroup Discovery**, identified execution of `net.exe` or `net1.exe` with arguments such as `user`, `users`, and `localgroup`, activity commonly used to list local accounts and group memberships on compromised hosts. The changes align with well-documented adversary behavior in **MITRE ATT&CK** techniques `T1087.001` and `T1069.001`, where threat actors use commands like `net user`, `net user /domain`, and `net localgroup administrators` to gather account and privilege information that can support privilege escalation and lateral movement. Splunk said the removed analytics were deprecated in version `5.2.0` in favor of **Windows User Discovery Via Net** and **Windows Group Discovery Via Net**, with the original detections having relied on EDR process telemetry, Sysmon `Event ID 1`, Windows Security `Event ID 4688`, and related endpoint data sources.
Aug 12, 2026