Sigma Rules
3,132 rules found for "sigma"
Registry Disable System Restore
Detects the modification of the registry to disable a system restore on the computer
Windows Defender Service Disabled - Registry
Detects when an attacker or tool disables the Windows Defender service (WinDefend) via the registry
Windows Event Log Access Tampering Via Registry
Detects changes to the Windows EventLog channel permission values. It focuses on changes to the Security Descriptor Definition Language (SDDL) string, as modifications to these values can restrict access to specific users or groups, potentially aiding in defense evasion by controlling who can view or modify a event log channel. Upon execution, the user shouldn't be able to access the event log channel via the event viewer or via utilities such as "Get-EventLog" or "wevtutil".
Disable Windows Firewall by Registry
Detect set EnableFirewall to 0 to disable the Windows firewall
Disable Windows Event Logging Via Registry
Detects tampering with the "Enabled" registry key in order to disable Windows logging of a Windows event channel
Add DisallowRun Execution to Registry
Detect set DisallowRun to 1 to prevent user running specific computer program
Persistence Via Disk Cleanup Handler - Autorun
Detects when an attacker modifies values of the Disk Cleanup Handler in the registry to achieve persistence via autorun. The disk cleanup manager is part of the operating system. It displays the dialog box […] The user has the option of enabling or disabling individual handlers by selecting or clearing their check box in the disk cleanup manager's UI. Although Windows comes with a number of disk cleanup handlers, they aren't designed to handle files produced by other applications. Instead, the disk cleanup manager is designed to be flexible and extensible by enabling any developer to implement and register their own disk cleanup handler. Any developer can extend the available disk cleanup services by implementing and registering a disk cleanup handler.
DNS-over-HTTPS Enabled by Registry
Detects when a user enables DNS-over-HTTPS. This can be used to hide internet activity or be used to hide the process of exfiltrating data. With this enabled organization will lose visibility into data such as query type, response and originating IP that are used to determine bad actors.
New DNS ServerLevelPluginDll Installed
Detects the installation of a DNS plugin DLL via ServerLevelPluginDll parameter in registry, which can be used to execute code in context of the DNS server (restart required)
ETW Logging Disabled In .NET Processes - Sysmon Registry
Potential adversaries stopping ETW providers recording loaded .NET assemblies.
Directory Service Restore Mode(DSRM) Registry Value Tampering
Detects changes to "DsrmAdminLogonBehavior" registry value. During a Domain Controller (DC) promotion, administrators create a Directory Services Restore Mode (DSRM) local administrator account with a password that rarely changes. The DSRM account is an “Administrator” account that logs in with the DSRM mode when the server is booting up to restore AD backups or recover the server from a failure. Attackers could abuse DSRM account to maintain their persistence and access to the organization's Active Directory. If the "DsrmAdminLogonBehavior" value is set to "0", the administrator account can only be used if the DC starts in DSRM. If the "DsrmAdminLogonBehavior" value is set to "1", the administrator account can only be used if the local AD DS service is stopped. If the "DsrmAdminLogonBehavior" value is set to "2", the administrator account can always be used.
Periodic Backup For System Registry Hives Enabled
Detects the enabling of the "EnablePeriodicBackup" registry value. Once enabled, The OS will backup System registry hives on restarts to the "C:\Windows\System32\config\RegBack" folder. Windows creates a "RegIdleBackup" task to manage subsequent backups. Registry backup was a default behavior on Windows and was disabled as of "Windows 10, version 1803".
Windows Recall Feature Enabled - Registry
Detects the enabling of the Windows Recall feature via registry manipulation. Windows Recall can be enabled by setting the value of "DisableAIDataAnalysis" to "0". Adversaries may enable Windows Recall as part of post-exploitation discovery and collection activities. This rule assumes that Recall is already explicitly disabled on the host, and subsequently enabled by the adversary.
Enabling COR Profiler Environment Variables
Detects .NET Framework CLR and .NET Core CLR "cor_enable_profiling" and "cor_profiler" variables being set and configured.
Scripted Diagnostics Turn Off Check Enabled - Registry
Detects enabling TurnOffCheck which can be used to bypass defense of MSDT Follina vulnerability
Potential EventLog File Location Tampering
Detects tampering with EventLog service "file" key. In order to change the default location of an Evtx file. This technique is used to tamper with log collection and alerting
Suspicious Application Allowed Through Exploit Guard
Detects applications being added to the "allowed applications" list of exploit guard in order to bypass controlled folder settings
Change User Account Associated with the FAX Service
Detect change of the user account associated with the FAX service to avoid the escalation problem.
Change the Fax Dll
Detect possible persistence using Fax DLL load when service restart
FileFix - Command Evidence in TypedPaths
Detects commonly-used chained commands and strings in the most recent 'url' value of the 'TypedPaths' key, which could be indicative of a user being targeted by the FileFix technique.
New File Association Using Exefile
Detects the abuse of the exefile handler in new file association. Used for bypass of security products.
Add Debugger Entry To Hangs Key For Persistence
Detects when an attacker adds a new "Debugger" value to the "Hangs" key in order to achieve persistence which will get invoked when an application crashes
Persistence Via Hhctrl.ocx
Detects when an attacker modifies the registry value of the "hhctrl" to point to a custom binary
Registry Modification to Hidden File Extension
Hides the file extension through modification of the registry
Displaying Hidden Files Feature Disabled
Detects modifications to the "Hidden" and "ShowSuperHidden" explorer registry values in order to disable showing of hidden files and system files. This technique is abused by several malware families to hide their files from normal users.
Registry Hide Function from User
Detects registry modifications that hide internal tools or functions from the user (malware like Agent Tesla, Hermetic Wiper uses this technique)
Hide Schedule Task Via Index Value Tamper
Detects when the "index" value of a scheduled task is modified from the registry Which effectively hides it from any tooling such as "schtasks /query" (Read the referenced link for more information about the effects of this technique)
Driver Added To Disallowed Images In HVCI - Registry
Detects changes to the "HVCIDisallowedImages" registry value to potentially add a driver to the list, in order to prevent it from loading.
IE ZoneMap Setting Downgraded To MyComputer Zone For HTTP Protocols
Detects changes to Internet Explorer's (IE / Windows Internet properties) ZoneMap configuration of the "HTTP" and "HTTPS" protocols to point to the "My Computer" zone. This allows downloaded files from the Internet to be granted the same level of trust as files stored locally.
Uncommon Extension In Keyboard Layout IME File Registry Value
Detects usage of Windows Input Method Editor (IME) keyboard layout feature, which allows an attacker to load a DLL into the process after sending the WM_INPUTLANGCHANGEREQUEST message. Before doing this, the client needs to register the DLL in a special registry key that is assumed to implement this keyboard layout. This registry key should store a value named "Ime File" with a DLL path. IMEs are essential for languages that have more characters than can be represented on a standard keyboard, such as Chinese, Japanese, and Korean.
Suspicious Path In Keyboard Layout IME File Registry Value
Detects usage of Windows Input Method Editor (IME) keyboard layout feature, which allows an attacker to load a DLL into the process after sending the WM_INPUTLANGCHANGEREQUEST message. Before doing this, the client needs to register the DLL in a special registry key that is assumed to implement this keyboard layout. This registry key should store a value named "Ime File" with a DLL path. IMEs are essential for languages that have more characters than can be represented on a standard keyboard, such as Chinese, Japanese, and Korean.
New Root or CA or AuthRoot Certificate to Store
Detects the addition of new root, CA or AuthRoot certificates to the Windows registry
Internet Explorer DisableFirstRunCustomize Enabled
Detects changes to the Internet Explorer "DisableFirstRunCustomize" value, which prevents Internet Explorer from running the first run wizard the first time a user starts the browser after installing Internet Explorer or Windows.
Potential Ransomware Activity Using LegalNotice Message
Detect changes to the "LegalNoticeCaption" or "LegalNoticeText" registry values where the message set contains keywords often used in ransomware ransom messages
Lolbas OneDriveStandaloneUpdater.exe Proxy Download
Detects setting a custom URL for OneDriveStandaloneUpdater.exe to download a file from the Internet without executing any anomalous executables with suspicious arguments. The downloaded file will be in C:\Users\redacted\AppData\Local\Microsoft\OneDrive\StandaloneUpdaterreSignInSettingsConfig.json
Lsass Full Dump Request Via DumpType Registry Settings
Detects the setting of the "DumpType" registry value to "2" which stands for a "Full Dump". Technique such as LSASS Shtinkering requires this value to be "2" in order to dump LSASS.
RestrictedAdminMode Registry Value Tampering
Detects changes to the "DisableRestrictedAdmin" registry value in order to disable or enable RestrictedAdmin mode. RestrictedAdmin mode prevents the transmission of reusable credentials to the remote system to which you connect using Remote Desktop. This prevents your credentials from being harvested during the initial connection process if the remote server has been compromise
Potential Persistence Via Netsh Helper DLL - Registry
Detects changes to the Netsh registry key to add a new DLL value. This change might be an indication of a potential persistence attempt by adding a malicious Netsh helper
New Netsh Helper DLL Registered From A Suspicious Location
Detects changes to the Netsh registry key to add a new DLL value that is located on a suspicious location. This change might be an indication of a potential persistence attempt by adding a malicious Netsh helper
NET NGenAssemblyUsageLog Registry Key Tamper
Detects changes to the NGenAssemblyUsageLog registry key. .NET Usage Log output location can be controlled by setting the NGenAssemblyUsageLog CLR configuration knob in the Registry or by configuring an environment variable (as described in the next section). By simplify specifying an arbitrary value (e.g. fake output location or junk data) for the expected value, a Usage Log file for the .NET execution context will not be created.
New Application in AppCompat
A General detection for a new application in AppCompat. This indicates an application executing for the first time on an endpoint.
Potential Credential Dumping Attempt Using New NetworkProvider - REG
Detects when an attacker tries to add a new network provider in order to dump clear text credentials, similar to how the NPPSpy tool does it
New ODBC Driver Registered
Detects the registration of a new ODBC driver.
Potentially Suspicious ODBC Driver Registered
Detects the registration of a new ODBC driver where the driver is located in a potentially suspicious location
Trust Access Disable For VBApplications
Detects registry changes to Microsoft Office "AccessVBOM" to a value of "1" which disables trust access for VBA on the victim machine and lets attackers execute malicious macros without any Microsoft Office warnings.
Microsoft Office Protected View Disabled
Detects changes to Microsoft Office protected view registry keys with which the attacker disables this feature.
Python Function Execution Security Warning Disabled In Excel - Registry
Detects changes to the registry value "PythonFunctionWarnings" that would prevent any warnings or alerts from showing when Python functions are about to be executed. Threat actors could run malicious code through the new Microsoft Excel feature that allows Python to run within the spreadsheet.
Enable Microsoft Dynamic Data Exchange
Enable Dynamic Data Exchange protocol (DDE) in all supported editions of Microsoft Word or Excel.