Detect Modify Registry in Splunk
Adversaries may interact with the Windows Registry to aid in defense evasion, persistence, and execution. The Registry may be modified to hide configuration information or malicious payloads, disable security controls (e.g., enabling WDigest plaintext credential caching, disabling Windows Defender, enabling Office macros), establish persistence via run keys or services, and store C2 configuration data. Common tools include the built-in reg.exe utility, PowerShell registry cmdlets (Set-ItemProperty, New-Item), and direct Win32 API calls (RegSetValueEx, RegCreateKeyEx). Adversaries may also target remote registries over SMB using valid accounts, or employ null-byte prefix tricks to create pseudo-hidden keys invisible to standard utilities.
MITRE ATT&CK
- Tactic
- Defense Evasion Persistence
- Technique
- T1112 Modify Registry
- Canonical reference
- https://attack.mitre.org/techniques/T1112/
SPL Detection Query
index=wineventlog (sourcetype="XmlWinEventLog:Microsoft-Windows-Sysmon/Operational" (EventCode=12 OR EventCode=13 OR EventCode=14))
OR (sourcetype="WinEventLog:Security" EventCode=4657)
| eval RegistryPath=coalesce(TargetObject, ObjectName)
| eval ValueName=coalesce(Details, ObjectValueName)
| eval ProcessName=coalesce(Image, ProcessName)
| eval UserName=coalesce(User, SubjectUserName)
| eval IsPersistenceKey=if(match(RegistryPath, "(?i)(CurrentVersion\\Run|CurrentVersion\\RunOnce|Winlogon|\\Services\\|Image File Execution Options)"), 1, 0)
| eval IsDefenseEvasionKey=if(match(RegistryPath, "(?i)(Lsa|Windows Defender|Policies\\\\System|\\\\Office\\|ZoneMap)"), 1, 0)
| eval IsWDigestEnable=if(match(RegistryPath, "(?i)Lsa") AND match(ValueName, "(?i)UseLogonCredential"), 1, 0)
| eval IsDefenderDisable=if(match(RegistryPath, "(?i)Windows Defender") AND match(ValueName, "(?i)(DisableAntiSpyware|DisableRealtimeMonitoring|DisableAntiVirus)"), 1, 0)
| eval IsMacroEnable=if(match(RegistryPath, "(?i)\\\\Security") AND match(ValueName, "(?i)VBAWarnings"), 1, 0)
| eval IsUACBypass=if(match(RegistryPath, "(?i)Policies\\\\System") AND match(ValueName, "(?i)(EnableLUA|ConsentPromptBehaviorAdmin)"), 1, 0)
| eval IsIFEO=if(match(RegistryPath, "(?i)Image File Execution Options") AND match(ValueName, "(?i)Debugger"), 1, 0)
| eval IsWinlogonHijack=if(match(RegistryPath, "(?i)Winlogon") AND match(ValueName, "(?i)(Userinit|Shell)"), 1, 0)
| eval IsSuspiciousProcess=if(match(ProcessName, "(?i)(powershell\.exe|pwsh\.exe|cmd\.exe|wscript\.exe|cscript\.exe|mshta\.exe|rundll32\.exe|regsvr32\.exe|msbuild\.exe|wmic\.exe|certutil\.exe|reg\.exe)"), 1, 0)
| eval RiskScore=IsPersistenceKey + IsDefenseEvasionKey + IsWDigestEnable*3 + IsDefenderDisable*3 + IsMacroEnable + IsUACBypass*2 + IsIFEO*2 + IsWinlogonHijack*3 + IsSuspiciousProcess
| where (IsPersistenceKey=1 OR IsDefenseEvasionKey=1) AND RiskScore > 0
| table _time, host, UserName, ProcessName, EventCode, RegistryPath, ValueName,
IsPersistenceKey, IsDefenseEvasionKey, IsWDigestEnable, IsDefenderDisable,
IsMacroEnable, IsUACBypass, IsIFEO, IsWinlogonHijack, IsSuspiciousProcess, RiskScore
| sort - RiskScore, - _timeDetects suspicious registry modifications using Sysmon Event IDs 12 (Registry key create/delete), 13 (Registry value set), and 14 (Registry key/value rename), supplemented by Security Event ID 4657 (registry value modified, requires SACL auditing). Evaluates modifications against known persistence and defense evasion registry paths, assigning weighted risk scores. High-risk patterns (WDigest enablement, Defender disablement, Winlogon hijacking) carry elevated scores. Results sorted by risk score to surface highest-priority events first.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Software installation and update processes legitimately modify Run keys and service registry entries — filter by known installer parent processes (msiexec.exe, setup.exe with code-signed paths)
- Group Policy application modifies Defender and Office macro policy keys during scheduled policy refreshes (gpscript.exe parent)
- Endpoint management agents (SCCM, Intune) that configure system settings via registry modifications during software deployment
- Legitimate security hardening scripts executed by IT administrators using reg.exe or PowerShell to apply CIS benchmarks
Other platforms for T1112
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Add Persistence via Run Key using reg.exe
Expected signal: Sysmon Event ID 13 (RegistryEvent - Value Set): TargetObject=HKCU\Software\Microsoft\Windows\CurrentVersion\Run\df00tech_test, Details=C:\Windows\System32\cmd.exe /c echo persistence_test, Image=C:\Windows\System32\reg.exe. Sysmon Event ID 1 (Process Create): Image=reg.exe with CommandLine showing add and Run key path. Security Event ID 4657 if SACL auditing is configured on the Run key.
- Test 2Enable WDigest Plaintext Credential Caching
Expected signal: Sysmon Event ID 13: TargetObject=HKLM\SYSTEM\CurrentControlSet\Control\Lsa\UseLogonCredential, Details=DWORD (0x00000001), Image=C:\Windows\System32\reg.exe. Security Event ID 4657 (if SACL configured on LSA key): OldValue=0 or empty, NewValue=1. Process creation event for reg.exe with the full command line visible.
- Test 3Disable Windows Defender via Registry
Expected signal: Sysmon Event ID 13: TargetObject=HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\DisableAntiSpyware, Details=DWORD (0x00000001). If Tamper Protection is active: Windows Defender Event ID 5001 (Real-time protection disabled) or Event ID 5013 (Tamper protection blocked change) in Microsoft-Windows-Windows Defender/Operational log. Process creation: reg.exe with DisableAntiSpyware in command line.
- Test 4IFEO Debugger Injection for Sticky Keys Backdoor
Expected signal: Sysmon Event ID 13: TargetObject=HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\sethc.exe\Debugger, Details=C:\Windows\System32\cmd.exe, Image=reg.exe. Sysmon Event ID 1 for reg.exe with full command line. If the backdoor is triggered: Sysmon Event ID 1 showing sethc.exe spawning cmd.exe from the winlogon.exe parent context.
References (12)
- https://attack.mitre.org/techniques/T1112/
- https://learn.microsoft.com/en-us/sysinternals/downloads/reghide
- https://learn.microsoft.com/en-us/sysinternals/downloads/regdelnull
- https://technet.microsoft.com/en-us/library/cc732643.aspx
- https://technet.microsoft.com/en-us/library/cc754820.aspx
- https://docs.microsoft.com/windows/security/threat-protection/auditing/event-4657
- https://posts.specterops.io/hiding-registry-keys-with-psreflect-b18ec5ac8353
- https://blog.trendmicro.com/trendlabs-security-intelligence/poweliks-malware-hides-in-windows-registry/
- https://unit42.paloaltonetworks.com/new-babyshark-malware-targets-u-s-national-security-think-tanks/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1112/T1112.md
- https://github.com/SigmaHQ/sigma/tree/master/rules/windows/registry
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceregistryevents-table
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