Sigma Rules
1,405 rules found for "Nextron Systems"
Potential AMSI COM Server Hijacking
Detects changes to the AMSI come server registry key in order disable AMSI scanning functionalities. When AMSI attempts to starts its COM component, it will query its registered CLSID and return a non-existent COM server. This causes a load failure and prevents any scanning methods from being accessed, ultimately rendering AMSI useless
AMSI Disabled via Registry Modification
Detects attempts to disable AMSI (Anti-Malware Scan Interface) by modifying the AmsiEnable registry value. Anti-Malware Scan Interface (AMSI) is a security feature in Windows that allows applications and services to integrate with anti-malware products for enhanced protection against malicious content. Adversaries may attempt to disable AMSI to evade detection by security software, allowing them to execute malicious scripts or code without being scanned.
New BgInfo.EXE Custom DB Path Registry Configuration
Detects setting of a new registry database value related to BgInfo configuration. Attackers can for example set this value to save the results of the commands executed by BgInfo in order to exfiltrate information.
New BgInfo.EXE Custom VBScript Registry Configuration
Detects setting of a new registry value related to BgInfo configuration, which can be abused to execute custom VBScript via "BgInfo.exe"
New BgInfo.EXE Custom WMI Query Registry Configuration
Detects setting of a new registry value related to BgInfo configuration, which can be abused to execute custom WMI query via "BgInfo.exe"
Bypass UAC Using SilentCleanup Task
Detects the setting of the environement variable "windir" to a non default value. Attackers often abuse this variable in order to trigger a UAC bypass via the "SilentCleanup" task. The SilentCleanup task located in %windir%\system32\cleanmgr.exe is an auto-elevated task that can be abused to elevate any file with administrator privileges without prompting UAC.
ClickOnce Trust Prompt Tampering
Detects changes to the ClickOnce trust prompt registry key in order to enable an installation from different locations such as the Internet.
Security Event Logging Disabled via MiniNt Registry Key - Registry Set
Detects the addition of the 'MiniNt' key to the registry. Upon a reboot, Windows Event Log service will stop writing events. Windows Event Log is a service that collects and stores event logs from the operating system and applications. It is an important component of Windows security and auditing. Adversary may want to disable this service to disable logging of security events which could be used to detect their activities.
Service Binary in Suspicious Folder
Detect the creation of a service with a service binary located in a suspicious directory
Windows Credential Guard Disabled - Registry
Detects attempts to disable Windows Credential Guard by setting registry values to 0. Credential Guard uses virtualization-based security to isolate secrets so that only privileged system software can access them. Adversaries may disable Credential Guard to gain access to sensitive credentials stored in the system, such as NTLM hashes and Kerberos tickets, which can be used for lateral movement and privilege escalation.
Windows Defender Exclusions Added - Registry
Detects the Setting of Windows Defender Exclusions
Potentially Suspicious Desktop Background Change Via Registry
Detects registry value settings that would replace the user's desktop background. This is a common technique used by malware to change the desktop background to a ransom note or other image.
Antivirus Filter Driver Disallowed On Dev Drive - Registry
Detects activity that indicates a user disabling the ability for Antivirus mini filter to inspect a "Dev Drive".
Windows Hypervisor Enforced Code Integrity Disabled
Detects changes to the HypervisorEnforcedCodeIntegrity registry key and the "Enabled" value being set to 0 in order to disable the Hypervisor Enforced Code Integrity feature. This allows an attacker to load unsigned and untrusted code to be run in the kernel
Hypervisor Enforced Paging Translation Disabled
Detects changes to the "DisableHypervisorEnforcedPagingTranslation" registry value. Where the it is set to "1" in order to disable the Hypervisor Enforced Paging Translation feature.
Disabled Windows Defender Eventlog
Detects the disabling of the Windows Defender eventlog as seen in relation to Lockbit 3.0 infections
Potential AutoLogger Sessions Tampering
Detects tampering with autologger trace sessions which is a technique used by attackers to disable logging
Disable Internal Tools or Feature in Registry
Detects registry modifications that change features of internal Windows tools (malware like Agent Tesla uses this technique)
Disable Macro Runtime Scan Scope
Detects tampering with the MacroRuntimeScanScope registry key to disable runtime scanning of enabled macros
Windows Defender Service Disabled - Registry
Detects when an attacker or tool disables the Windows Defender service (WinDefend) via the registry
Disable Windows Event Logging Via Registry
Detects tampering with the "Enabled" registry key in order to disable Windows logging of a Windows event channel
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.
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)
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".
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
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.
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
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.
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.
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
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.
Potential Persistence Via Outlook LoadMacroProviderOnBoot Setting
Detects the modification of Outlook setting "LoadMacroProviderOnBoot" which if enabled allows the automatic loading of any configured VBA project/module
Outlook EnableUnsafeClientMailRules Setting Enabled - Registry
Detects an attacker trying to enable the outlook security setting "EnableUnsafeClientMailRules" which allows outlook to run applications or execute macros
Uncommon Microsoft Office Trusted Location Added
Detects changes to registry keys related to "Trusted Location" of Microsoft Office where the path is set to something uncommon. Attackers might add additional trusted locations to avoid macro security restrictions.
Macro Enabled In A Potentially Suspicious Document
Detects registry changes to Office trust records where the path is located in a potentially suspicious location
Office Macros Warning Disabled
Detects registry changes to Microsoft Office "VBAWarning" to a value of "1" which enables the execution of all macros, whether signed or unsigned.
MaxMpxCt Registry Value Changed
Detects changes to the "MaxMpxCt" registry value. MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate. Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
Potential Persistence Via New AMSI Providers - Registry
Detects when an attacker adds a new AMSI provider via the Windows Registry to bypass AMSI (Antimalware Scan Interface) protections. Attackers may add custom AMSI providers to persist on the system and evade detection by security software that relies on AMSI for scanning scripts and other content. This technique is often used in conjunction with fileless malware and script-based attacks to maintain persistence while avoiding detection.