Furthermore, Protected Mode can send only specific window messages to higher integrity processes. By preventing unauthorized access to sensitive areas of a user's system, Protected Mode limits the amount of damage that can be caused by a compromised IE process.
An attacker cannot, for example, silently install a keystroke logger to the user's Startup folder. Likewise, a compromised process cannot manipulate applications on the desktop through window messages. Of course, these defenses also limit legitimate changes to higher integrity locations. As a result, Protected Mode provides a compatibility architecture that reduces the impact on existing extensions, as shown in the following figure.
Compatibility Layer handles the needs of many existing extensions. The compatibility layer uses a Windows Compatibility Shim to automatically redirect these operations to the following low integrity locations:. Two higher privilege broker processes allow Internet Explorer and extensions to perform elevated operations given user consent. For example, the user privilege broker IEUser.
In addition, an administrator privilege broker IEInstal. To verify that Internet Explorer is running in Protected mode, look for the words "Protected Mode: On" next to the Web content zone displayed in Internet Explorer's status bar.
This section shows how extensions can perform common tasks while in Protected Mode. It explains how to find low integrity object locations, save files outside low integrity file locations, elevate processes out of Protected Mode, and debug Protected Mode access failures. In Windows Vista, securable objects automatically inherit the lower integrity level between the process that created them and their container.
As a result, files or registry keys have a low integrity when created in Protected Mode. This means that a low integrity process can obtain write access to the objects it creates. However, a low integrity process cannot gain write access to medium or high integrity folders or files in the user's profile.
However, extensions running in Protected Mode's low integrity process can write only to specific low integrity locations and should use IEGetWriteableHKCU to obtain a low integrity registry location. Some extensions need to save files to a particular location so that users or applications can later find the files.
The following steps show how to save a file outside of a low integrity location:. Remember to delete the temporary file after the file is sucessfully saved. Call IEShowSaveFileDialog with the location of the user's profile folder to prompt the user to save the file in a different location. When you do this, Protected Mode's user broker copies the file from the temporary location to the location selected by the user.
To obtain write access to other medium integrity objects, use a custom broker process and then elevate your broker to a medium level process. When run as medium level processes, broker objects can access medium integrity objects.
For more information, see Starting Processes from Protected Mode. In general, extensions should operate as low integrity processes whenever possible. This provides the best protection against malicious attacks. However, there are times when an extension may need to access medium or even high integrity objects. To do this, create a broker process to access higher integrity objects and then launch the broker process with a higher integrity level.
By default, Internet Explorer will prompt the user to confirm the medium integrity elevated process, as shown in the following screen shot. Set the name of the new key to the GUID created for your policy and then add the following settings to the key:. The following table describes the supported values.
To illustrate, the following policy would silently elevate a fictional broker called contoso. If Microsoft determines that an application has a vulnerability and presents a danger to end users, Microsoft reserves the right to remove that application at any time from the elevation policy. You can also create broker processes to access high integrity objects. For information describing how to launch broker processes with a high integrity level, please see the Guidelines for Administrative User Applications section of Developer Best Practices and Guidelines for Applications in a Least Privileged Environment.
Note that you do not need to create an elevation policy because UAC will handle the elevation. If your existing extension uses rundll The following example shows the setting that would silently load the fictional contoso. By default, Protected Mode prompts the user before allowing web content to be copied to a higher integrity process.
You can register your application to avoid this prompt and silently accept web content from a drag-and-drop operation by creating a DragDrop policy. Next, add a key to the following location. Policy DWORD should be set to 3, which tells Protected mode to allow web content to be silently copied to your application process. The following example shows the setting that would allow web content to be silently copied to fictional contoso.
As mentioned above, UIPI blocks window messages from low to higher integrity processes. If your extension running in Protected mode needs to communicate with an evelated application using window messages, you can call ChangeWindowMessageFilter from the elevated application to allow specific messages though. Note that a high integrity process with administrator privileges will launch a high integrity IE process with Protected Mode off.
If you want to launch Protected Mode from your high integrity process, then first create a medium integrity process, which will launch your high integrity process and IE. You can continue controlling navigations after IE is launched only if your application has the same integrity level as the IE process launched. First of all, you should know that besides displaying the elevation prompts, UAC is responsible for a couple of other security-related settings:.
Some applications store settings or user data in areas of the registry or file system that are meant to be used only by the system. This is an unnecessary use of administrative rights and a security risk. File system and registry virtualization diverts attempts to write to the system locations to the ones in user locations while keeping application compatibility. Turning off UAC disables file system and registry virtualization.
As a side effect some applications might not work and for others you will loose existing settings. If a malicious web page exploits a bug in IE or an IE plug-in, that code will not be able to do damage to the system.
The recommended way of getting rid of the prompts is to disable them while keeping other UAC features on. Actually this method only affects administrators running in admin approval mode the account created during Windows 7 setup that you are probably using right now is such an account , the behavior of UAC on standard accounts remains the same.
You will be presented with a long list of settings and among them 10 are related to User Account Control. With the built-in UAC elevation component, members of the local Administrators group can easily perform an administrative task by providing approval. The default, built-in UAC elevation component for an administrator account in Admin Approval Mode is called the consent prompt. With UAC enabled, Windows 10 or Windows 11 prompts for consent or prompts for credentials of a valid local administrator account before starting a program or task that requires a full administrator access token.
This prompt ensures that no malicious software can be silently installed. The consent prompt is presented when a user attempts to perform a task that requires a user's administrative access token. The following is an example of the UAC consent prompt. The credential prompt is presented when a standard user attempts to perform a task that requires a user's administrative access token. Administrators can also be required to provide their credentials by setting the User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode policy setting value to Prompt for credentials.
The UAC elevation prompts are color-coded to be app-specific, enabling for immediate identification of an application's potential security risk.
When an app attempts to run with an administrator's full access token, Windows 10 or Windows 11 first analyzes the executable file to determine its publisher.
Apps are first separated into three categories based on the file's publisher: Windows 10 or Windows 11, publisher verified signed , and publisher not verified unsigned. The following diagram illustrates how Windows determines which color elevation prompt to present to the user. Some Control Panel items, such as Date and Time Properties , contain a combination of administrator and standard user operations. Standard users can view the clock and change the time zone, but a full administrator access token is required to change the local system time.
The shield icon on the Change date and time button indicates that the process requires a full administrator access token and will display a UAC elevation prompt. The elevation process is further secured by directing the prompt to the secure desktop. The consent and credential prompts are displayed on the secure desktop by default in Windows 10 and Windows Only Windows processes can access the secure desktop. For higher levels of security, we recommend keeping the User Account Control: Switch to the secure desktop when prompting for elevation policy setting enabled.
When an executable file requests elevation, the interactive desktop, also called the user desktop, is switched to the secure desktop. The secure desktop dims the user desktop and displays an elevation prompt that must be responded to before continuing.
When the user clicks Yes or No , the desktop switches back to the user desktop. Malware can present an imitation of the secure desktop, but when the User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode policy setting is set to Prompt for consent , the malware does not gain elevation if the user clicks Yes on the imitation.
If the policy setting is set to Prompt for credentials , malware imitating the credential prompt may be able to gather the credentials from the user. However, the malware does not gain elevated privilege and the system has other protections that mitigate malware from taking control of the user interface even with a harvested password. While malware could present an imitation of the secure desktop, this issue cannot occur unless a user previously installed the malware on the PC.
Because processes requiring an administrator access token cannot silently install when UAC is enabled, the user must explicitly provide consent by clicking Yes or by providing administrator credentials. If the operation changes the file system or registry, Virtualization is called.
All other operations call ShellExecute. ShellExecute calls CreateProcess. If it receives the error, ShellExecute calls the Application Information service to attempt to perform the requested task with the elevated prompt. A system service that helps start apps that require one or more elevated privileges or user rights to run, such as local administrative tasks, and apps that require higher integrity levels.
The Application Information service helps start such apps by creating a new process for the application with an administrative user's full access token when elevation is required and depending on Group Policy consent is given by the user to do so.
Notify me only when programs try to make changes to my computer do not dim my desktop will:. The User Account Control: Switch to the secure desktop when prompting for elevation policy setting is checked:. If the secure desktop is enabled, all elevation requests go to the secure desktop regardless of prompt behavior policy settings for administrators and standard users. If the secure desktop is not enabled, all elevation requests go to the interactive user's desktop, and the per-user settings for administrators and standard users are used.
CreateProcess calls AppCompat, Fusion, and Installer detection to assess if the app requires elevation. The file is then inspected to determine its requested execution level, which is stored in the application manifest for the file. The AppCompat database stores information in the application compatibility fix entries for an application. The Fusion database stores information from application manifests that describe the applications. The manifest schema is updated to add a new requested execution level field.
Installer detection detects setup files, which helps prevent installations from being run without the user's knowledge and consent. Virtualization technology ensures that non-compliant apps do not silently fail to run or fail in a way that the cause cannot be determined. UAC also provides file and registry virtualization and logging for applications that write to protected areas.
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