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AppLocker

AppLocker is a feature in Windows operating systems that enables administrators to define rules allowing or denying the execution of specific applications, scripts, and files based on attributes such as publisher, file path, hash, or version, thereby helping organizations enforce software restrictions and mitigate risks from unauthorized or malicious code. Introduced with and , AppLocker builds on earlier application control mechanisms like Software Restriction Policies, providing a more granular and user-friendly approach to whitelisting approved software while blocking others. It supports enforcement of rules for executable files (.exe, .com), scripts (such as .bat, .cmd, .ps1, .vbs, .js), packages (.msi, .msp, .mst), dynamic-link libraries (DLLs, .dll, .ocx), and packaged apps, allowing policies to be applied to individual users, groups, or the entire system via or Local . Key benefits include preventing execution, ensuring compliance with licensing and organizational standards, and standardizing the software environment across endpoints, with features like audit-only mode for testing rules before full enforcement and cmdlets for automated management. AppLocker integrates with broader Windows tools, such as App Control for Business (formerly Windows Defender Application Control), to provide scalable deployment in enterprise settings, though it requires the Application Identity service to be running and is not supported on installations.

Overview

Definition and Purpose

AppLocker is a Group Policy-based application control feature in Windows that allows system administrators to define and enforce rules for allowing or denying the execution of applications, scripts, and installers based on attributes such as file publishers, paths, or hashes. This capability enables precise management of software execution at the enterprise level, supporting both whitelisting (explicitly allowing approved files) and (explicitly denying specific files) approaches. The core purpose of AppLocker is to prevent unauthorized or malicious software from running on Windows devices, thereby reducing the risk of infections and enhancing overall system in organizational environments. By enforcing application control policies, it helps organizations maintain compliance with standards and regulatory requirements, limiting the potential for unauthorized applications to compromise data or resources. In practice, AppLocker promotes a default-deny posture where only vetted applications are permitted, significantly mitigating the compared to unrestricted execution. AppLocker evolved from the earlier Software Restriction Policies (SRP) introduced in , providing more flexible and granular rule conditions without fully supplanting SRP, which remains available for on older systems. This progression allows for easier auditing of software usage patterns and supports the principle of least privilege by restricting users and processes to only necessary applications. As a result, it lowers administrative overhead in managing endpoints and contributes to cost savings by decreasing the incidence of security incidents related to rogue software.

Key Features

AppLocker provides granular control over application execution through rules based on multiple criteria, enabling administrators to allow or deny files such as executables (.exe, .com), scripts (.bat, .cmd, .js, .ps1, .vbs), packages (.msi, .msp, .mst), dynamic-link libraries (.dll, .ocx), and packaged apps. These rules can be defined using publisher information derived from digital signatures (including company name, product name, file name, and ), file paths (with support for environment variables like %WINDIR% or %PROGRAMFILES%), or file hashes for unique identification. This flexibility allows for precise targeting, such as permitting all applications from a trusted publisher except those below a certain , and supports exceptions within rules to refine permissions without creating multiple overlapping policies. To ensure system stability and prevent administrative lockouts, AppLocker includes default allow rules that automatically permit execution of core Windows components, such as files in the Windows and Program Files directories, for all users, as well as full access for members of the Administrators group. These built-in rules provide a safety net, allowing essential operations to proceed even when custom policies are enforced. An audit-only mode enables policy testing by logging potential rule violations without blocking application launches, which helps administrators assess the impact of rules on user workflows before full enforcement. This mode generates detailed event logs for analysis, supporting iterative refinement of policies. For enterprise environments, AppLocker integrates with Group Policy Objects (GPOs) via the Group Policy Management Console, facilitating centralized deployment and management of rules across multiple computers in a . Policies can be created on a , exported using , and imported for production use, ensuring consistent application control without manual configuration on each device. Comprehensive reporting is available through , where AppLocker logs track both allowed and denied executions, capturing details such as the user account, application path, and rule that triggered the event. These logs, generated in or modes, allow for monitoring compliance and troubleshooting, with cmdlets providing options for programmatic data extraction and analysis.

History and Development

Origins and Initial Release

AppLocker was developed by as an advanced application control mechanism to succeed Software Restriction Policies (SRP), which had been introduced in 2 in 2004 to restrict unauthorized software execution but suffered from limitations in rule flexibility and administrative manageability, particularly in large-scale enterprise deployments. This evolution addressed the need for more intuitive policy creation based on file attributes like publisher, , or , enabling finer-grained control over executables, scripts, and installers without relying solely on path-based restrictions. The primary motivations for AppLocker's creation stemmed from the escalating threats during the mid-2000s, as cyber attacks increasingly targeted through unauthorized applications, prompting a shift toward proactive whitelisting strategies over reactive . Additionally, it responded to demands for compliance with industry standards, where robust controls are required to prevent unapproved software from compromising sensitive data and ensuring audit-ready application governance. These enhancements were conceptualized as part of broader Windows improvements during the development of , aiming to simplify protection for IT administrators managing diverse user environments. AppLocker made its initial release on October 22, 2009, alongside and , integrated as a built-in feature available in the and editions of , as well as all editions of . This debut marked a significant step in enterprise , providing domain-based enforcement to limit application execution and mitigate risks from malicious or unauthorized code. Early adoption focused on organizational IT administrators leveraging to enforce policies across endpoints, particularly in corporate networks where controlling software proliferation was essential for maintaining security posture and operational efficiency. Over subsequent Windows versions, AppLocker expanded in scope and accessibility, but its foundational role in application whitelisting remained tied to these initial enterprise-oriented implementations.

Evolution Across Windows Versions

Following its initial release in Enterprise and Ultimate editions and in 2009, AppLocker underwent significant enhancements starting with and in 2012, primarily to address the growing ecosystem of modern applications. A key addition was for packaged apps, including those distributed through the , enabling administrators to create rules for both packaged app installers and the apps themselves using publisher-based conditions. This extension allowed for more granular control over Metro-style (now ) applications, which were not covered by traditional executable, , or installer rules in prior versions. Additionally, scripting rule enforcement was refined to better integrate with emerging application types, though core support remained consistent from earlier iterations. In and , released in 2013, AppLocker received optimizations to its rule mechanisms. These updates built on the packaged app capabilities, ensuring compatibility with evolving app deployment models while maintaining backward compatibility with policies. AppLocker remained available only in Enterprise editions for clients. The introduction of and in 2015 marked a pivotal shift toward integrated security ecosystems, with AppLocker gaining supplemental functionality through Windows Defender Application Control (WDAC), a more advanced code integrity solution. WDAC provided extensible policy options that complemented AppLocker's allow/deny model, such as enhanced kernel-level enforcement and supplemental driver blocking, while AppLocker itself saw improved auditing for script rules. Compatibility with (MDM) protocols was also bolstered, enabling remote policy deployment via tools like , which facilitated management in enterprise mobile scenarios. By the era, Software Restriction Policies (SRP), the predecessor to AppLocker, were effectively phased out in favor of AppLocker and WDAC for modern deployments. Windows 11 and , launched in 2021 and 2022 respectively, emphasized cloud-native administration, with AppLocker policies now seamlessly deployable through Microsoft Endpoint Manager (formerly Intune) for hybrid environments. This allowed centralized, cloud-based rule updates and auditing, reducing on-premises management burdens. Logging capabilities were enhanced for compliance, providing detailed event data in for better integration with (SIEM) systems, including timestamps and rule violation contexts. As of 2025, AppLocker in updates, including version 24H2 and support in 2025, features minor refinements such as policy controls for AI-driven features like Copilot Chat, enabling restrictions on AI application executions without major architectural overhauls. These changes support hybrid work by strengthening MDM integrations and threat logging, aligning with broader security postures like Zero Trust, while maintaining core compatibility with prior versions. No significant deprecations have occurred, but continues to recommend transitioning to WDAC for advanced scenarios.

Functionality

Rule Types and Policies

AppLocker rules are categorized into five primary collections that define the types of files subject to control, enabling administrators to restrict application execution based on specific file formats and behaviors. Executable rules apply to files with .exe and .com extensions, preventing unauthorized programs from running on the system. DLL rules apply to dynamic-link libraries with .dll and .ocx extensions, controlling the loading of libraries to enhance against unauthorized or malicious DLLs; this collection is not enabled by default due to potential performance impacts and application compatibility issues. rules govern installation packages, targeting .msi, .msp, and .mst files to control and updates. Script rules manage scripting languages commonly used for , including .bat, .cmd, .js, .ps1, and .vbs files, to mitigate risks from malicious scripts. Packaged app rules focus on modern application formats, such as AppX and MSIX packages for (UWP) and desktop apps, ensuring only approved store or sideloaded applications can execute. Each rule within these collections relies on one or more conditions to identify applicable files precisely, allowing for flexible yet targeted enforcement. Publisher-based conditions use digital signatures, including the issuer, product name, file version, and name, to allow or block files from trusted vendors; this method is resilient to file relocations but requires updates for version changes. Path-based conditions specify exact file locations or folders in the or network shares, supporting environment variables like %PROGRAMFILES% and wildcards for broader coverage, such as allowing all files in a directory except subfolders. Hash-based conditions employ cryptographic file hashes (SHA-256 or similar) for exact matches, ideal for controlling specific, unchanging files like custom tools, though they necessitate recreation if files are modified or updated. Extension-based conditions, often implemented via path rules with wildcards (e.g., *.exe), enable blocking or allowing files by their type without specifying full paths, providing a simple way to restrict entire categories like executables. AppLocker policies organize these rules into structured collections within Group Policy Objects (GPOs), facilitating centralized management across domains. Rules are grouped into allow lists, which explicitly permit specified files or users, and deny lists, which block them, with deny actions overriding allows for precedence; exceptions can be defined within rules to carve out allowances for particular users, groups, or subconditions, such as permitting a specific version despite a broader denial. Policies inherit hierarchically from domain-level GPOs down to Organizational Units (OUs), allowing granular application while merging rules from parent containers unless explicitly overridden. By default, AppLocker operates in a deny-all for each rule collection once enforcement is enabled, blocking any file not explicitly allowed to enforce strict whitelisting and prevent unauthorized code execution. This configurable fallback ensures comprehensive control, though administrators can audit events in monitor-only before full enforcement to refine policies without disruptions.

Enforcement Mechanisms

AppLocker evaluates rules at execution time through the (appid.sys), a kernel-mode driver that attempts to run executables, DLLs, scripts, files, and packaged apps. This occurs before the file is loaded, where appid.sys reads the effective policy—cached for executables and DLLs to minimize repeated evaluations—and checks the file against the configured rules. If the rule collection for a file type is enforced but contains no rules, all files of that type are denied by default. The evaluation prioritizes explicit deny rules over allow rules across all applicable conditions (publisher, path, or file hash); a file matching any deny rule is blocked regardless of matching allow rules, while files must match at least one allow rule if the collection has rules. For executables and DLLs, enforcement happens in kernel mode for enhanced security, whereas scripts and files are evaluated in user mode via the . This process integrates with (UAC), applying rules to both standard and elevated contexts during privilege checks. AppLocker operates in two primary modes: Audit only and Enforce rules, configurable per rule collection. In Audit only mode, rules are evaluated without blocking execution, generating log events for allowed (Event IDs 8002 and 8005) or would-be-blocked files (Event IDs 8003 and 8006) to facilitate policy testing and monitoring. In Enforce rules mode, matching deny rules prevent execution—either silently or with user notifications indicating the block—while logging allowed (Event IDs 8002 and 8005) or blocked files (Event IDs 8004 and 8007). All events are recorded in the Windows under Applications and Services Logs > Microsoft > Windows > AppLocker, with sublogs for EXE and DLL, MSI and Script, and Packaged app rules. Each event includes details such as the file or app identifier, process name, user or group (), type (e.g., publisher or ), name, and the reason for the match or block. This supports without impacting . For error handling, AppLocker resolves rule conflicts by enforcing deny precedence, ensuring no ambiguous allowances; if policy application fails (e.g., due to GPO issues), it falls back to the previous effective or a default deny state for configured collections. The system handles elevation requests through UAC integration, evaluating rules against the requested context to prevent unauthorized escalations. Performance impact is minimal overall, thanks to appid.sys caching rule evaluations for executables and DLLs, which avoids repeated reads during sessions. However, enabling DLL rule collections introduces slight overhead from per-load checks, though this is typically imperceptible; optimizing involves limiting rules per GPO and preferring publisher over conditions to reduce evaluation complexity.

Configuration and Management

Creating and Applying Rules

AppLocker rules are created and managed primarily through the Local Security Policy editor (secpol.msc) for standalone systems or the Group Policy Management Editor (gpedit.msc or via Group Policy Management Console) for domain environments. To begin, administrators navigate to Computer Configuration > Windows Settings > Security Settings > Application Control Policies > AppLocker, where they can select specific rule collections such as Executable rules, Windows Installer rules, Script rules, or Packaged app rules. Creating rules involves a wizard-based process within the AppLocker console. For publisher rules, which rely on digital signatures for identification, the process starts by right-clicking the appropriate rule collection and selecting Create New Rule. After specifying permissions (allow or deny for users or groups), the wizard prompts selection of the "Publisher rule condition." Administrators then browse to a signed , such as an , to extract details including publisher name, product name, file name, and ; a slider allows scoping from the full certificate chain down to file version, with options for wildcards (e.g., "*") in fields to broaden or narrow matching. Exceptions can be added to exclude specific sub-conditions. Path rules, suitable for controlling based on locations, follow a similar but select the "Path rule condition" after permissions. Administrators browse or manually enter folder paths (e.g., "C:\Program Files[Microsoft Office](/page/Microsoft_Office)"), with support for environment variables like %OSDRIVE% and options to include or exclude subfolders. This allows granular control, such as permitting executables only from system directories while blocking others. Exceptions for specific paths within the rule can also be defined. File rules identify applications by their cryptographic , providing a content-based match independent of location or . In the , after selecting "File hash rule condition," administrators browse to one or more files (or folders for multiple), and the system automatically computes Authenticode cryptographic hashes. These rules are ideal for unsigned or custom applications but require recalculation if files update. For scripting scenarios, cmdlets like New-AppLockerRule can be used to create rules by providing file paths, as the cmdlet internally computes the required hashes. Once rules are defined, policies are applied by linking Group Policy Objects (GPOs) to Organizational Units (OUs) in the Management Console, targeting specific computers or users. Enforcement is enabled by setting the policy to "Enforce rules" in the AppLocker properties, though initial deployment should use "Audit only" mode to log violations without blocking, allowing review via (under Applications and Services Logs > Microsoft > Windows > AppLocker). Policies propagate automatically during Group Policy refresh intervals, but immediate application can be forced with the command gpupdate /force on target machines. Testing in a controlled environment helps identify unintended blocks before full enforcement. Note that in version 24H2, a temporary issue prevented proper enforcement of script rules for Constrained Language Mode, which was resolved in the May 2025 cumulative update (KB5058411). Ensure systems are updated for full functionality. Common scenarios include whitelisting productivity applications, such as creating publisher rules to allow the entire suite by selecting any Office executable and setting the scope to the Corporation publisher certificate, ensuring only signed versions run. Another frequent use is blocking executables on by defining a deny path rule for "%REMOVABLE%" with enabled, preventing unauthorized software from portable drives. These approaches balance security with operational needs in enterprise settings. For basic troubleshooting, administrators can configure custom notifications to inform users of restrictions when a blocked application is attempted, such as displaying a with policy details or support instructions via registry settings under HKLM\SOFTWARE\Policies[Microsoft](/page/Microsoft)\Windows\AppLocker. Event logs in provide details on blocked or audited events, aiding in rule refinement without disrupting users.

Administrative Tools and Interfaces

AppLocker policies in enterprise environments are primarily managed through core interfaces integrated with Windows management tools. The Group Policy Management Console (GPMC) serves as the central interface for configuring and deploying AppLocker policies across Active Directory domains, allowing administrators to create, edit, and link Group Policy Objects (GPOs) that enforce rules on multiple machines simultaneously. For standalone or non-domain-joined systems, the Local Group Policy Editor (gpedit.msc) provides a graphical interface to define and apply AppLocker policies locally, enabling rule management without domain infrastructure. Advanced scripting and automation capabilities extend management beyond graphical tools. Windows cmdlets, such as New-AppLockerPolicy for generating rules from file lists and Get-AppLockerPolicy for retrieving existing from local or sources, facilitate bulk rule creation, policy merging, and testing in scripted workflows. Although AppLocker's core interfaces are not publicly exposed as a general for third-party custom applications, programmatic access is available through the AppLocker Configuration (CSP), which leverages WMI providers for policy configuration in managed device scenarios. In hybrid and cloud-managed setups, AppLocker integrates with broader endpoint management platforms for scalable deployment. (formerly SCCM) supports AppLocker by designating it as a managed installer, allowing policies to tag and authorize applications deployed via Configuration Manager while enforcing restrictions on unauthorized software. For cloud-based (MDM), enables AppLocker policy delivery through the AppLocker CSP, supporting hybrid environments where policies are pushed to Windows devices for enforcement of executable, script, and MSI rules. Monitoring AppLocker enforcement relies on built-in logging tools, with providing detailed audit trails of policy applications, including blocked or allowed executions, user contexts, and file paths under the Applications and Services Logs\Microsoft\Windows\AppLocker path. These logs can be exported and integrated with third-party (SIEM) systems, such as , for centralized aggregated reporting and correlation with other security events across the enterprise. Further automation is achieved via (WMI) providers, which expose AppLocker policy states and rule details through classes like MDM_AppLocker_EXE03 for restrictions, enabling remote querying and updates in scripts or management tools. This WMI-based access supports programmatic monitoring and adjustment of enforcement modes without manual intervention.

Availability and Compatibility

Supported Windows Editions

AppLocker is available in select editions of Windows client and server operating systems, with support evolving through updates to enable broader deployment across editions.

Client Editions

AppLocker was initially supported on Enterprise and Ultimate editions. In and 8.1, support extended to Enterprise editions for full configuration and enforcement, while Pro editions allowed configuration but not enforcement. For versions prior to 2004, AppLocker required Enterprise or Education editions for Group Policy-based enforcement. Following the release of KB5024351 in February 2023, edition restrictions were removed, enabling configuration and enforcement of AppLocker policies on all editions of and later, as well as all editions of , including and . This update allows deployment via (MDM) on editions without additional registry modifications, though local enforcement on editions remains limited to policy application without native cmdlets for advanced management. As of November 2025, no further changes to core edition availability have occurred, and AppLocker functions on ARM-based devices, including version 24H2, consistent with general App Control for Business support.

Server Editions

AppLocker received full support starting with Enterprise and Datacenter editions. Subsequent versions, including , 2012 R2, 2016, 2019, and 2022, provide support across all editions, with policies enforceable via . 2025 maintains this availability without alterations to edition requirements.

Limitations

AppLocker is unavailable on Home or Standard editions of Windows versions predating the KB5024351 update, and it does not support Windows editions below or non-listed server variants. On Windows 10 Pro editions prior to version 2004, activation required specific or registry configurations for enforcement.

Prerequisites

Domain-based AppLocker policies necessitate an environment for deployment, while local policies can be applied without it. Kernel-level enforcement requires a 64-bit Windows installation and standard hardware meeting the OS minimum specifications, such as sufficient for policy evaluation.
Windows VersionSupported Client EditionsSupported Server Editions
Enterprise, UltimateN/A
Windows 8/8.1Enterprise (full), Pro (config only)N/A
(pre-2004)Enterprise, EducationN/A (Server separate)
(2004+) / All (Home, Pro, Enterprise, Education)All editions
N/AEnterprise, Datacenter
Windows Server 2012+ (incl. 2022, 2025)N/AAll editions

Version-Specific Features and Limitations

AppLocker's capabilities have evolved significantly across Windows versions, with each iteration introducing new rule types or deployment options while retaining certain constraints tied to the underlying operating system architecture. Initial releases focused on basic file-based controls, while later versions integrated support for modern application formats and enhanced management through (MDM) tools. The following table summarizes key version-specific features and limitations, based on official documentation.
Windows VersionNew FeaturesLimitations
Windows 7 / Server 2008 R2Introduced core rule types for executables (.exe, .com), scripts (.ps1, .bat, .cmd, .vbs, .js), Windows Installer files (.msi, .msp), and DLLs (.dll, .ocx); audit-only mode for testing policies; rules based on publisher, path, hash, or file properties.No support for packaged app rules; configuration and enforcement limited to Enterprise and Ultimate editions; lacked native MDM or cloud-based policy deployment; hash rules required manual recomputation for any file modifications, increasing administrative overhead.
Windows 8 / Server 2012Added packaged app and packaged app installer rules (.appx, .mst) for Microsoft Store applications; publisher rules specifically for signed packaged apps.Enforcement still restricted to Enterprise edition for client OS; no integration with emerging device management frameworks like Intune; continued fragility of hash rules with software updates altering file hashes.
Windows 8.1 / Server 2012 R2Enhanced rule management with PowerShell cmdlets for automation; improved exception handling in policies.Pro edition could configure but not enforce policies; absent support for later cloud integrations; performance degradation on systems with extensive hash-based rules due to computational demands.
Windows 10 / Server 2016+Full integration with Windows Defender Application Control (WDAC) for hybrid policies; MDM support via Intune for cloud deployment; post-KB5024351 (2023), enforcement enabled on all editions starting from version 2004; expanded script rule coverage including PowerShell.Hash rules remain vulnerable to breakage from automatic updates or file versioning, necessitating frequent policy maintenance; notable performance overhead on low-end hardware during hash verification for large rule sets; no native controls for Windows Subsystem for Linux (WSL) binaries.
Windows 11Builds on Windows 10 with refined WDAC convergence for Zero Trust architectures; improved handling of modern packaged apps and scripts in audit mode; alignment with Smart App Control features for baseline protection.Enforcement unavailable in S mode due to its restrictive Store-only app ecosystem; persistent hash rule maintenance challenges with frequent OS updates; disabled by default in consumer-focused configurations without MDM; lacks direct support for non-Win32 subsystems like WSL; script enforcement broken in version 24H2, where PowerShell Constrained Language Mode is not enforced correctly, allowing bypass of script rules as of November 2025.
In earlier versions like Windows 7 and Server 2008 R2, AppLocker's audit mode provided basic logging but lacked the granular event details and integration with advanced analytics available in later releases, complicating initial policy testing. Modern implementations in Windows 10 and 11 address some of these through enhanced event viewing in Event Viewer and MDM synchronization, yet hash-based rules continue to pose maintenance burdens, as even minor file alterations—such as security patches—invalidate them, potentially disrupting legitimate applications. In Windows 11 version 24H2 and Windows Server 2025, an ongoing issue prevents proper enforcement of script rules for PowerShell, failing to apply Constrained Language Mode as of November 2025. As of 2025, AppLocker aligns with Zero Trust principles via its role in App Control for Business, enabling supplemental use of WDAC for scenarios like unsigned executables or environments lacking full AppLocker support, such as or legacy hardware. This hybrid approach mitigates limitations in version-specific enforcement while preserving compatibility across enterprise deployments.

Security Considerations

Bypass Techniques

AppLocker's path rules, which restrict execution based on file locations, can be circumvented through techniques such as DLL hijacking, where a malicious is placed in an application's search path within an untrusted directory, allowing a whitelisted to load and run unauthorized . This bypass is possible if AppLocker DLL rules are not configured. Hash rules, relying on file checksums like SHA-256 for identification, are vulnerable to slight modifications of whitelisted files, which alter the hash value and necessitate constant rule updates to maintain coverage; without updates, the changed files execute unimpeded. A (TOCTOU) exacerbates this, particularly over network shares, where attackers intercept and modify file contents between AppLocker's multiple validation reads, allowing altered executables to pass initial checks. Publisher rules, which permit execution based on digital signatures, can be bypassed by leveraging Microsoft-signed Windows tools such as rundll32.exe or regsvr32.exe to load and execute arbitrary code, as these utilities are inherently trusted and exempt from strict or scrutiny. Weak or self-signed certificates also facilitate circumvention, enabling attackers to repackage malicious binaries with forged signatures that mimic legitimate publishers. Script and installer evasions often involve encoding payloads to change file extensions or employing alternative loaders like mshta.exe, which interprets applications containing code, or cscript.exe and wscript.exe for execution, thereby sidestepping restrictions on direct script files. As of 2025, emerging techniques include DLL side-loading with allowed executables, where threat actors substitute legitimate DLLs with malicious ones loaded by trusted binaries like regsvr32.exe to execute under the guise of approved software. Additionally, AppLocker's audit mode, intended for policy testing, permits full execution while logging violations, allowing of rule boundaries through repeated attempts without enforcement interruptions.

Mitigation Strategies and Best Practices

To enhance the resilience of AppLocker policies, administrators should prioritize publisher-based rules over or rules, as publisher rules leverage signatures to identify applications by vendor, product, file name, and version, thereby accommodating updates without frequent reconfiguration. Implementing multiple rule layers, such as combining allow rules with deny exceptions, enables granular control; for instance, an allow rule for a can include exceptions to block specific high-risk components like registry editors for non-administrative users. This layered approach minimizes disruptions while maintaining , as deny exceptions take precedence and allow targeted exclusions without broad policy overhauls. Effective monitoring involves regularly reviewing AppLocker event logs in the Windows , particularly Event IDs 8003 and 8004, which record authorized and unauthorized executions to identify potential policy gaps. Integrating these logs with (SIEM) systems, such as , facilitates through automated analysis of application launch patterns. Periodic audits, recommended at least annually or following significant environmental changes, validate rule efficacy by cross-referencing against organizational needs and refining policies accordingly. Best practices for AppLocker deployment include initiating policies in audit-only mode to establish a baseline of application usage without enforcement, allowing administrators to log activities and iteratively build comprehensive rules. Combining AppLocker with Windows Defender Application Control (WDAC) and antivirus solutions like provides defense-in-depth, where AppLocker handles user-mode restrictions and WDAC extends to kernel-mode protections. User education on policy impacts, such as notifying staff about restricted applications and providing escalation paths for legitimate needs, reduces support incidents and promotes compliance. For advanced mitigations, enabling Smart App Control in complements AppLocker by automatically blocking unsigned or untrusted code using cloud-based reputation checks, particularly beneficial for endpoint devices. To address script-based risks, enforcing Constrained Language Mode in via AppLocker policies limits advanced scripting features, preventing unsigned scripts from executing malicious code while allowing approved operations. As of 2025, leveraging Defender for Endpoint's behavioral analysis integrates AppLocker event data to detect and respond to post-policy execution attempts, enhancing real-time threat hunting through unified dashboards and automated alerts. This update supports Windows Server 2025 environments, ensuring seamless policy enforcement across hybrid deployments.

References

  1. [1]
    AppLocker - Microsoft Learn
    Oct 1, 2024 · AppLocker helps you control which apps and files users can run. These include executable files, scripts, Windows Installer files, dynamic-link libraries (DLLs) ...App Control for Business · AppLocker design guide · Administer AppLocker
  2. [2]
    What Is AppLocker | Microsoft Learn
    Oct 1, 2024 · AppLocker helps you create rules to allow or deny apps from running based on information about the apps' files.
  3. [3]
    Working with AppLocker rules - Microsoft Learn
    Oct 1, 2024 · This article for IT professionals describes AppLocker rule types and how to work with them for your application control policies.
  4. [4]
    App Control for Business and AppLocker Overview - Microsoft Learn
    Mar 10, 2025 · AppLocker was introduced with Windows 7, and allows organizations to control which applications are allowed to run on their Windows clients.
  5. [5]
    AppLocker technical reference - Microsoft Learn
    Oct 1, 2024 · AppLocker lets you create rules to allow or deny apps from running based on information about the apps' files. You can specify unique rules for ...
  6. [6]
    Use AppLocker and Software Restriction Policies in the Same Domain
    Aug 31, 2016 · AppLocker is supported on systems running Windows 7 and above. Software Restriction Policies (SRP) is supported on systems running Windows Vista or earlier.
  7. [7]
    Software Restriction Policies Technical Overview | Microsoft Learn
    Jul 29, 2021 · AppLocker policies can be updated by using the Local Security Policy snap-in (if the policies are created locally), or the GPMC, or the Windows ...
  8. [8]
    Understand AppLocker policy design decisions - Microsoft Learn
    Oct 1, 2024 · AppLocker policies can be applied through a Group Policy Object (GPO) to computer objects within an organizational unit (OU). Individual ...Which Apps Do You Need To... · Comparing Classic Windows... · Using Applocker To Control...
  9. [9]
    What Is AppLocker? - Microsoft Learn
    Aug 30, 2016 · AppLocker helps reduce administrative overhead and helps reduce the organization's cost of managing computing resources by decreasing the number ...
  10. [10]
    Administer AppLocker - Microsoft Learn
    Oct 1, 2024 · You can administer AppLocker policies using the Group Policy Management Console to create or edit a Group Policy Object (GPO).
  11. [11]
    Windows AppLocker's Lockdown Limitations - EdTech Magazine
    Apr 3, 2012 · Windows AppLocker is a feature of Windows 7 and Windows Server 2008 R2 that lets administrators control what types of programs are allowed ...
  12. [12]
    Windows 7 - Microsoft Lifecycle
    Start Date, Mainstream End Date, Extended End Date. Windows 7, Oct 22, 2009, Jan 13, 2015, Jan 14, 2020. Releases. Expand table. Version, Start Date, End Date ...Fixed Lifecycle Policy · Desktop Deployment Center · Extended Security Updates
  13. [13]
    Software Restriction Policies | Microsoft Learn
    Jan 16, 2023 · Software Restriction Policies were deprecated ... You should use Windows Defender Application Control (WDAC) or AppLocker to control what software ...
  14. [14]
  15. [15]
    Requirements to use AppLocker | Microsoft Learn
    Oct 1, 2024 · Skip to main content Skip to Ask Learn chat ... The following table shows the Windows versions on which AppLocker features are supported.Missing: key | Show results with:key
  16. [16]
    Understanding AppLocker rule collections - Microsoft Learn
    Feb 24, 2025 · This article explains the five different types of AppLocker rule collections used to enforce AppLocker policies.
  17. [17]
    Understanding AppLocker rule condition types - Microsoft Learn
    Oct 1, 2024 · Primary conditions are required to create an AppLocker rule. The three primary rule conditions are publisher, path, and file hash.
  18. [18]
    Understanding AppLocker allow and deny actions on rules
    Oct 1, 2024 · Each AppLocker rule collection functions as an explicit allowlist of files. You can only run files that are covered by one or more allow rules within the rule ...
  19. [19]
    AppLocker processes and interactions - Microsoft Learn
    Oct 1, 2024 · An AppLocker rule collection is a set of rules that apply to one of the following types: executable files, Windows Installer files, scripts, ...
  20. [20]
    Enforce AppLocker rules - Microsoft Learn
    Oct 1, 2024 · When AppLocker policy enforcement is set to Audit only, rules are only evaluated but events generated from that evaluation are written to the ...Missing: process | Show results with:process
  21. [21]
    Using Event Viewer with AppLocker - Microsoft Learn
    Oct 1, 2024 · In the console tree under Application and Services Logs\Microsoft\Windows, select AppLocker. ... No packaged apps can be executed while Exe ...
  22. [22]
    Optimize AppLocker performance - Microsoft Learn
    Oct 1, 2024 · This article for IT professionals describes how to optimize AppLocker policy enforcement. Optimization of Group Policy
  23. [23]
    Create Your AppLocker rules - Microsoft Learn
    Oct 1, 2024 · This article for the IT professional describes what you need to know about AppLocker rules and the methods that you can to create rules.
  24. [24]
    Create a rule that uses a publisher condition
    ### Step-by-Step Process for Creating a Publisher Rule in AppLocker
  25. [25]
    Create a rule that uses a path condition
    ### Step-by-Step Process for Creating a Path Rule in AppLocker
  26. [26]
    Create a rule that uses a file hash condition
    ### Step-by-Step Process for Creating a File Hash Rule in AppLocker
  27. [27]
    Get-FileHash (Microsoft.PowerShell.Utility)
    The Get-FileHash cmdlet computes a unique hash value for a file's content, using a specified algorithm, to verify content integrity.
  28. [28]
    Create Your AppLocker policies - Microsoft Learn
    Oct 1, 2024 · You can create or modify AppLocker policies by using the Group Policy Management Console (GPMC), or you can import an AppLocker policy into a ...Step 1: Use your plan · Step 2: Create your rules and...
  29. [29]
    Display a custom URL message when users try to run a blocked app
    Oct 1, 2024 · This article for IT professionals describes the steps for displaying a customized message to users when an AppLocker policy blocks an app.
  30. [30]
    Tools to use with AppLocker | Microsoft Learn
    Oct 1, 2024 · The AppLocker log contains information about applications affected by AppLocker rules. For info about using Event Viewer to review the AppLocker ...<|separator|>
  31. [31]
    Use the AppLocker Windows PowerShell cmdlets - Microsoft Learn
    Oct 1, 2024 · To edit or update a Group Policy Object (GPO) by using the AppLocker cmdlets, you must have Edit Setting permission. By default, members of the ...Applocker Windows Powershell... · Retrieve Application... · Generate Rules For A Given...<|control11|><|separator|>
  32. [32]
    New-AppLockerPolicy (AppLocker) | Microsoft Learn
    The New-AppLockerPolicy cmdlet uses a list of file information to automatically generate a list of rules for a given user or group.
  33. [33]
    Get-AppLockerPolicy (AppLocker) | Microsoft Learn
    The Get-AppLockerPolicy cmdlet retrieves the AppLocker policy from the local Group Policy Object (GPO), a specified GPO, or the GP-deployed effective policy ...Syntax · LocalPolicy (Default) · Description
  34. [34]
    Security considerations for AppLocker | Microsoft Learn
    Oct 1, 2024 · The enforcement mode settings from AppLocker policies distributed through Group Policy Objects (GPO) take precedence over local policies.Missing: kernel | Show results with:kernel
  35. [35]
    AppLocker CSP - Microsoft Learn
    Mar 12, 2025 · The AppLocker configuration service provider is used to specify which applications are allowed or disallowed.Applocker Csp · Familysafety · Policy Xsd SchemaMissing: key | Show results with:key
  36. [36]
    Manage Windows Defender Application Control - Microsoft Learn
    Dec 16, 2024 · Setting up Configuration Manager as a managed installer on devices uses a Windows AppLocker policy. AppLocker is only used to identify managed ...Supported Operating Systems · Before You Start · Security And Privacy...
  37. [37]
    MDM_AppLocker_ApplicationLa...
    Oct 28, 2024 · The MDM_AppLocker_ApplicationLaunchRestrictions01_EXE03 class allows you to specify which EXE applications are allowed to launch.
  38. [38]
    KB5024351—Removal of Windows edition checks for AppLocker
    These updates removed the edition checks for Windows 10, versions 2004, 20H2, and 21H1 and all versions of Windows 11. You can now deploy and enforce AppLocker ...
  39. [39]
    App Control for Business feature availability | Microsoft Learn
    Oct 1, 2024 · Capability, App Control for Business, AppLocker. Platform support, Available on Windows 10, Windows 11, and Windows Server 2016 or later.
  40. [40]
    What Is AppLocker?
    ### Supported Windows Editions and Versions for AppLocker
  41. [41]
    AppLocker Overview - Microsoft Learn
    Apr 10, 2019 · AppLocker helps administrators control which applications and files users can run. These include executable files, scripts, Windows Installer files, dynamic- ...
  42. [42]
    Understanding the file hash rule condition in AppLocker
    Oct 1, 2024 · This article explains how to use the AppLocker file hash rule condition and its advantages and disadvantages.
  43. [43]
    Packaged apps and packaged app installer rules in AppLocker
    Oct 1, 2024 · This article explains the AppLocker rule collection for packaged app installers and packaged apps. Packaged apps can be installed through the Microsoft Store.
  44. [44]
    Packaged Apps and Packaged App Installer Rules in AppLocker
    Aug 31, 2016 · This topic explains the AppLocker rule collection for packaged app installers and packaged apps introduced in Windows Server 2012 and Windows 8.
  45. [45]
    Windows 11 Security Book - Application And Driver Control
    Aug 4, 2025 · We've been making significant improvements to Smart App Control to increase the security, usability, and cloud intelligence response for apps in ...Smart App Control · App Control For Business · Administrator Protection
  46. [46]
    [PDF] Finding Evil in the Whitelist - GIAC Certifications
    Mar 23, 2015 · Application whitelisting technologies are extremely effective at reducing the ability for malicious code to run in an environment.
  47. [47]
    [PDF] Bypassing Windows AppLocker using a Time of Check ... - NCC Group
    Dec 4, 2013 · Windows AppLocker [1] [2] is Microsoft's replacement to Software Restriction Policies [3] [4] [5] in. Windows 7, Windows 8, Server 2008 and ...
  48. [48]
    Applications that can bypass App Control and how to block them
    Mar 10, 2025 · View a list of recommended block rules, based on knowledge shared between Microsoft and the wider security community.
  49. [49]
    Lumma Stealer: Breaking down the delivery techniques ... - Microsoft
    May 21, 2025 · This technique enables execution under the guise of a trusted binary to bypass behavioral detection and endpoint monitoring tools.
  50. [50]
    Configure an AppLocker policy for audit only - Microsoft Learn
    Oct 1, 2024 · This article for IT professionals describes how to set AppLocker policies to Audit only within your IT environment by using AppLocker.
  51. [51]
    Working with AppLocker Rules | Microsoft Learn
    Aug 31, 2016 · This topic describes AppLocker rule types and how to work with them for your application control policies using Windows Server® 2012 and Windows ...
  52. [52]
    Essential Eight application control - Microsoft Learn
    Mar 24, 2025 · Microsoft recommends that customers implement Windows Defender Application Control (WDAC) rather than AppLocker. Windows Defender Application ...
  53. [53]
    Application Control for Windows | Microsoft Learn
    Mar 10, 2025 · Application Control restricts which applications users are allowed to run and the code that runs in the system core.App Control for Business · Use the Smart App Control... · Example policyMissing: Restriction deprecated
  54. [54]
    PowerShell Constrained Language Mode - Microsoft Developer Blogs
    Nov 2, 2017 · Summary. PowerShell Constrained Language is designed to work with application whitelisting solutions in order to restrict what can be accessed ...