Engineering Windows 7 : Security

Safeguarding Windows 7 – Parental Controls

e7blog — Tue, 26 May 2009 10:00:00 GMT

As you can imagine, our team is quite busy working through this next phase of Windows 7. We definitely appreciate the millions of downloads and installs of the Windows 7 RC. Things are going as we expect at this point. On a personal note, I wanted to thank all the folks who have been sending me mail. I’ve received a lot of kind words and support regarding the RC and quite a few people saying “hurry up and just release it”. We outlined the steps we’re taking for this next milestone and aren’t going to rush things. We’ve got a lot of work for sure! Not that I’m counting, but I just crossed over 3,000 emails sent via the contact link in this blog. While I haven’t answered all of them, I’ve done the best I can, and appreciate each and every exchange.

Windows 7 includes a set of features for safeguarding your PC when used by children. This post is by Vladimir Rovinsky, a program manager on our Safety Team, who details the features in Windows 7 specifically around Parental Controls. This work is in addition to the safety of the OS itself and of course the features built into Internet Explorer to provide safety and security while browsing. You might also want to check out Windows Live Family Safety which is part of Windows Live Essentials (http://download.live.com) which provides even more for safety and parental controls. --Steven

Today, children are exposed to digital hazards more easily than any time in the past. Especially with the help of powerful search tools, convenient social networking applications, low cost tools and services for publishing videos and photographs, the web is awash with content that’s inappropriate for children, and full of people that parents want to bar from contacting their children.

These digital hazards are accessible to children through a variety of applications, including web browsers, instant messaging applications, media players, games, and email applications. Many of these applications have attempted to offer parental control features. However, they offer this functionality through variety of user interfaces, locations and include varied terminology. The duplication and inconsistency of parental control settings management can make it difficult for parents to maintain the correct settings across multiple applications.

Windows Vista Parental Controls provided a framework to solve these problems by offering:

A single, central location in the Windows Control Panel to configure and manage parental control settings and activities;
Built-in restrictions on web content and file downloads, time spent on the computer, application usage, game usage as well as the ability to log and view user activity.
The Windows Parental Control platform public application programming interfaces (API) which expose in-box restriction settings and logging functionality to any application. For instance, Internet Explorer and Mozilla Firefox 3.0 are using these APIs to determine if file downloads should be blocked for a user.
Integration with the User Account Control (UAC) to enforce standard user accounts for parentally controlled users; promotion of best practices for keeping kids safer on a Windows computer; for instance, encouraging the creation of separate standard accounts for managed children, password creation for parent accounts (administrators), etc.

To get a quick demo of Windows Vista Parental Controls in action, check out this video.

For more information about developing software for Windows Vista Parental Controls, see Using Parental Controls APIs.

Key Design Decisions for updates to Windows 7 Parental Controls

Responding to customer feedback and evolving nature of the web and challenges it poses to the parents, we strive to provide families with flexible and effective safety features. Our efforts for the Windows 7 release of Parental Controls were focused on the following objectives:

1. Further developing the extensibility of the Parental Controls platform to enable third-party developers to create richer Parental Control capabilities that integrate well with Windows 7 Parental Controls.

The Windows 7 Parental Controls platform was modified to allow multiple independent providers of Parental Controls functionality to be installed on the system and augment or fully replace the parental controls provided by Windows 7. Windows Vista allowed partial replacement of Windows Parental Controls; the web filter was replaceable. In Windows 7, in addition to the web filter components, the entire Windows 7 Parental Controls user interface can be replaced by third-party providers. The underlying enforcement of the offline restrictions will still be performed by Windows Parental Controls platform. Allowing a third party provider to replace the entire Windows Parental Controls user interface creates a consistent user experience that seamlessly combines existing Parental Controls functionality with the new ones introduced by the third-party provider.

The Windows Control Panel Parental Controls screen still remains the central location and launching point on Windows 7 for Parental Controls functionality regardless of whether it is provided by default (system) or by a third-party provider.

2. Removal of web content restrictions and activity viewing functionality from default (system) Parental controls provider and reliance on Windows Live or third-party providers for these capabilities.

The web is changing much faster than we can update the Windows operating system. For example, when Vista was released Social Networking was barely known. Now it has a thriving web presence. We need to keep web focused parental controls up with innovation. Because of this, we have moved them into Windows Live.

Web filtering and activity viewing capabilities can be more efficiently provided by Windows Live or a third-party solution that implement web based delivery of this functionality. For instance, Microsoft’s Windows Live Family Safety free application provides web content filtering, file downloads restrictions, and activity monitoring. It also provides online contact restrictions for children using Windows Live online applications (Windows Live Hotmail, Windows Live Messenger, etc).

You can learn more about Windows Live Family Safety solution here.

More information about Windows 7 changes to the Parental Controls platform can be found here.

Windows 7 Parental Controls User Interface Changes.

Elements new to Windows 7 Parental controls top-level screen can be seen on the following screen shot:

Figure 1 Windows 7 Parental Controls screen

The Additional controls section allows users to select a provider for additional controls such as web filtering, activity reporting, online contact management, etc. When a third-party controls provider’s installed on the computer, the screen displays the Select a provider drop down box that shows the currently selected (active) provider. A description of the provider’s functionality, as supplied by the provider, is shown below the drop down.
When the user account is selected by clicking user’s name or picture, the provider configuration for the user is launched. The provider can take over the default configuration UI for the in-box offline restrictions. Optionally, provider generated status strings for user accounts are displayed under user account pictures.
An Icon supplied by provider is shown in the upper right corner of the screen.

Additional control providers can still rely on the default’s (system) provider UI for the configuration of in-box offline restrictions. If a provider chooses to do so, the User Controls screen can be presented to configure a user’s Parental Controls settings.

If an additional provider is selected and configured, the following new user interface elements are shown on the Windows 7 User Controls screen:

Figure 2 Windows 7 User Controls screen. Additional controls provider is installed and configured.

More Settings allows direct access to the currently selected provider’s functionality.
Web Restrictions allows access to the currently selected provider’s functionality.

Windows Parental Controls settings and Vista to Windows 7 upgrade

If a Windows Vista PC which has parentally managed user accounts with enabled web filtering restrictions is upgraded to Windows 7, parents (administrators) are warned during the upgrade as well as when opening the Windows 7 Parental Controls screen, that web filtering and activity reporting functionality is not part of Windows 7 Parental Controls.

Figure 3 Windows 7 Parental Controls screen. Some users have web filtering restrictions. No additional provider is installed.

Windows Vista Parental Controls settings (including web filtering and activity logs information) are preserved unchanged when upgrading from Windows Vista to Windows 7. Although web filtering settings and activity logs information are not used by Windows 7 Parental controls, their preservation allows third-party provider to honor these settings.

As you start using Windows 7, we hope these changes to Parental Controls capabilities will make you feel more confident and in control of how your family members are using computers and experiencing the web.

--Vladimir

Improvements to AutoPlay

e7blog — Mon, 27 Apr 2009 10:00:00 GMT

As mentioned before on this blog (regarding our UAC changes) and on the IE blog (regarding the SmartScreen® filter for malware), we have an increased focus to enable customers to be in control and feel confident about the software that they choose to run on their computers. Folks on this blog have also commented about the concerns they have specifically in the AutoPlay area. This blog entry addresses some of the changes that we have made to increase customer confidence when using their media and devices with Windows. It is authored by Arik Cohen, a program manager on the Core User Experience team. –Steven [Note: There was a technical problem so this post was reposted in its entirety.]

Certain malware, including the Conficker worm, have started making use of the capabilities of AutoRun to provide a seemingly benign task to people – which masquerades as a Trojan Horse to get malware onto the computer. The malware then infects future devices plugged into that computer with the same Trojan Horse. For further information about Conficker please visit http://www.microsoft.com/protect/computer/viruses/worms/conficker.mspx

In the following example for a USB flash drive that has photos, malware registers as the benign task of “Open folders to view files.” If you select the first “Open folders to view files” (circled in red), you would be running malware. However, if you select the second task (circled in green), you would be safe running the Windows task.

Infected USB AutoPlay

People are confused why they have two tasks that appear to do the same thing – and even a knowledgeable person who is careful not to run software from an untrusted source can easily make the mistake of selecting the first task. As a result, people lose confidence and don’t feel in control.

A growing attack

While presenting an AutoRun task in AutoPlay has been available since Windows XP, we have seen a marked increase in the amount of malware that is using AutoRun as a potential method of propagation. According to the Security Intelligence Report, an enterprise study by Forefront Client Security found that the category of malware that can propagate via AutoRun accounted for 17.7% of infections in the second half of 2008 – the largest single category of malware infections.

The chart below shows the increasing amount of detection reports by Microsoft anti-virus software of the class of infections that spread via AutoRun. (Note: The actual method of infection cannot be determined.)

Infection Detections of Malware that Spread via AutoRun

Currently, disabling AutoPlay completely is the only solution for consumers and enterprises to gain confidence with the use of USB flash devices on their computer. Guidance on disabling AutoPlay is available here.

Increasing customer confidence

Windows 7 introduces key changes to AutoPlay that keep you from being exposed inadvertently to malware like Conficker when doing your common scenarios with devices (e.g., get to the files on your USB flash drive, download pictures from an SD card, etc.).

In particular, Windows will no longer display the AutoRun task in the AutoPlay dialog for devices that are not removable optical media (CD/DVD.) because there is no way to identify the origin of these entries. Was it put there by the IHV, a person, or a piece of malware? Removing this AutoRun task will block the current propagation method abused by malware and help customers stay protected. People will still be able to access all of the other AutoPlay tasks that are installed on their computer.

With these changes, if you insert a USB flash drive that has photos and has been infected by malware, you can be confident that the tasks displayed are all from software already on your computer:

Infected USB AutoPlay after AutoPlay changes

On the other hand, if you insert a CD that offers software to install, Windows will still display the AutoRun task provided by the ISV during their media creation process. For example:

AutoPlay for a CD that offers an AutoRun Task

You will first see this updated AutoRun experience in the Windows 7 RC build, and we will be bringing this change to Vista and XP in the future.

Ecosystem Impact

We are working with our ecosystem partners to help mitigate situations where this AutoRun change will have an impact on them.

CDs and DVDs (including CD emulation), where the IHV specified AutoRun task authored during manufacturing, will continue to provide the AutoRun choice allowing customers to run the specified software. IHVs of generic mass storage devices should expect that people will browse the contents of the device to launch any software. The new behavior will allow customers to continue to use AutoPlay (including all Windows and ISV installed tasks) to access their media and devices while not being presented with tasks from malware. Additionally, device classes, such as portable media players and cell phones, now support Device Stage™ on Windows 7. Device Stage offers the IHV a multifunction alternative to AutoPlay where they can present links to software and common tasks, and provides additional features as you use the device.

As you try out the Windows 7 RC, we hope these changes will make you feel more confident and in control when using your media and devices.

-Arik Cohen

UAC Feedback and Follow-Up

e7blog — Fri, 06 Feb 2009 02:00:00 GMT

When we started the “E7” blog we were both excited and also a bit uneasy. The excitement is obvious. The unease is because at some point we knew we would mess up. We weren’t sure if we would mess up because we were blogging about a poorly designed feature or mess up because we were blogging poorly about a well-designed feature. To some it appears as though with the topic of UAC we’ve managed to do both. Our dialog is at that point where many do not feel listened to and also many feel various viewpoints are not well-informed. That’s not the dialog we set out to have and we’re going to do our best to improve.

This post is an attempt to get both the blog right and the feature right. We don’t like where we are in terms of how folks are feeling and we don’t feel good – Windows 7 is too much fun and folks are having too much fun for us to be having the dialog we’re having. We hope this post allows us to get back to having fun!

To start we’ll just show representative comments from the spectrum of feedback. We’ll then talk about the changes we’re making and also make sure we’re all on the same page regarding how we move forward. In terms of comments we’ve heard the following:

@sroussey says:

You have 95% of the people out there think you got it wrong, even if they are the ones that got it wrong. The problem is that they are the one's that buy and recommend your product. So do you give them a false sense of increased security by implementing the change (not unlike security by obscurity) and making them happy, or do you just fortify the real security boundaries?

And @Thack says:

Jon,

Thanks for sharing your thoughts. I understand your points.

Now, I want add my voice to the call for one very simple change:

Treat the UAC prompting level as a special case, such that ANY change to it, whether from the user or a program, generates a UAC prompt, regardless of the type of account the user has, and regardless of the current prompting level.

That is all we are asking. No other changes. Leave the default level as it is, and keep UAC as it is. We're just talking about the very specific case of CHANGES to the UAC prompting level.

It will NOT be a big nuisance - most people only ever change the UAC level once (if at all).

Despite your assurances, I REALLY WANT TO KNOW if anything tries to alter the UAC prompting level.

The fact that nobody has yet demonstrated how the putative malware can get into your machine is NO argument. Somebody WILL get past those other boundaries eventually.

Even if you aren't convinced by my argument, then the PR argument must be a no-brainer for Microsoft.

PLEASE, Jon, it's just a small change that will gain a LOT of user confidence and a LOT of good PR.

Thack

With this feedback and a lot more we are going to deliver two changes to the Release Candidate that we’ll all see. First, the UAC control panel will run in a high integrity process, which requires elevation. That was already in the works before this discussion and doing this prevents all the mechanics around SendKeys and the like from working. Second, changing the level of the UAC will also prompt for confirmation.

@mdaria510 says:

Sometimes, inconsistency with your own ideals is a good thing. Make an exception, if only to put people's fears to rest.

That sums up where we are heading. The first change was a bug fix and we actually have a couple of others similar to that—this is a beta still, even if many of us are running it full time. The second change is due directly to the feedback we’re seeing. This “inconsistency” in the model is exactly the path we’re taking. The way we‘re going to think about this that the UAC setting is something like a password, and to change your password you need to enter your old password.

The feedback is that UAC is special, because it can be used to disable silently future warnings if that change is not elevated and so to change the UAC setting an elevation will be required. To the points in the comments, we also don’t want to create a sense or expectation of security that is not there—you should still not download code and run it unless you trust the source. HTML, EXE, VBS, BAT, CMD and more are all code and all have the potential to alter the environment (user settings, user files) running as a standard user or an administrator. We’re focused on helping people make sure that code doesn’t get on the machine without consent and many third party tools can help more as well. We want people to be comfortable with the new UAC control and the new default setting, so we’ll make the changes outlined above as the feedback has been clear.

While we’re discussing this we want to make sure we’re all on the same page going forward in terms of how we will evaluate the security of Windows 7. Aside from the UAC setting, the discussion of the vulnerability aspects of the Windows 7 Beta have each started with getting code on the machine, which the mechanisms of Windows have prevented in the cases shown. We have also heard of security concerns that involve multiple steps to demonstrate a potential exploit. It is important to look at the first step—if the first step is “first get code running on the machine” then nothing after that is material, whether it is changing settings or anything else. We will treat very seriously the ability to get code on a machine and run without consent. As Jon’s post highlighted briefly, the work in Windows 7 is about the increased protections in place to secure your PC from acquiring and running code without your consent, and of course we continue to make sure Windows code is secure from both tampering or circumventing the protections in the system.

We want to reiterate the security of the system overall. Windows 7 is SD3+C and is designed to be more secure that Vista—that’s our priority. None of us want to have Windows 7 be perceived as being less secure than Vista in any way, because our design point is to make sure it is more secure that Windows Vista, by default.

We said we thought we were bound to make a mistake in the process of designing and blogging about Windows 7. We want to continue the dialog and hopefully everyone recognizes that engineering, perhaps especially engineering Windows 7, is sometimes going to be a lively discussion with a broad spectrum of viewpoints expressed. We don’t want the discussion to stop being so lively or the viewpoints to stop being expressed, but we do want the chance to learn and to be honest about what we learned and hope for the same in return. This blog has almost been like building an extra product for us, and we’re having a fantastic experience. Let’s all get back to work and to the dialog about Engineering Windows 7. And of course most importantly, we will continue to hear all points of view and share our point of view and work together to deliver a Windows 7 product that we can all feel good about.

--Jon and Steven

Update on UAC

e7blog — Thu, 05 Feb 2009 11:00:00 GMT

Hi, Jon DeVaan here to talk to you about the recent UAC feedback we’ve been receiving.

Most of our work finishing Windows 7 is focused on responding to feedback. The UAC feedback is interesting on a few dimensions of engineering decision making process. I thought that exploring those dimensions would make for an interesting e7 blog entry. This is our third discussion about UAC and for those interested in the evolution of the feature in Windows it is worth seeing the two previous posts (post #1 and post #2) and also reading the comments from many of you.

We are flattered by the response to the Windows 7 beta so far and working hard at further refining the product based on feedback and telemetry as we work towards the Release Candidate. For all of us working on Windows it is humbling to know that our work affects so many people around the world. The recent feedback is showing us just how much passion people have for Windows! Again we are humbled and excited to be a part of an amazing community of people working to bring the value of computing to a billion people around the world. Thank you very much for all of the thoughts and comments you have contributed so far.

UAC is one of those features that has a broad spectrum of viewpoints with advocates staking out both “ends” of the spectrum as well as all points in between, and often doing so rather stridently. In this case we might represent the ends of the spectrum as “security” on one end and “usability” on the other. Of course, this is not in reality a bi-polar issue. There is a spectrum of perfectly viable design points in between. Security experts around the world have lived with this basic tension forever, and there have certainly been systems designed to be so secure that they are secure from the people who are supposed to benefit from them. A personal example I have, is that my bank recently changed the security regimen on its online banking site. It is so convoluted I am switching banks. Seriously!

Clarifying Misperceptions

As people have commented on our current UAC design (and people have commented on those comments) it is clear that there is conflation of a few things, and a set of misperceptions that need to be cleared up before we talk about the engineering decisions made on UAC. These engineering decisions have been made while we carry forth our secure development lifecycle principles pioneered in Windows XP SP2, and most importantly the principle of “secure by default” as part of SD3+C. Windows 7 upholds those principles and does so with a renewed focus on making sure everyone feels they are in control of their PC experience as we have talked about in many posts.

The first issue to untangle is about the difference between malware making it onto a PC and being run, versus what it can do once it is running. There has been no report of a way for malware to make it onto a PC without consent. All of the feedback so far concerns the behavior of UAC once malware has found its way onto the PC and is running. Microsoft’s position that the reports about UAC do not constitute a vulnerability is because the reports have not shown a way for malware to get onto the machine in the first place without express consent. Some people have taken the, “it’s not a vulnerability” position to mean we aren’t taking the other parts of the issue seriously. Please know we take all of the feedback we receive seriously.

The word “vulnerability” has a very specific meaning in the security area. Microsoft has one of the leading security agencies in the world in the Microsoft Security Response Center (secure@microsoft.com) which monitors the greater ecosystem for security threats and manages the response to any threat or vulnerability related to Microsoft products. By any definition that is generally accepted across the world wide security community, the recent feedback does not represent a vulnerability since it does not allow the malicious software to reach the computer in the first place.

It is worth pointing out the defenses that exist in Windows Vista that keep malware from getting on the PC in the first place. In using Internet Explorer (other browsers have similar security steps as well) when attempting to browse to a .vbs file or .exe file, for example, the person will see the prompts below:

Internet Explorer 8 has also introduced many new features to thwart malware distribution (see http://blogs.msdn.com/ie/archive/2008/08/29/trustworthy-browsing-with-ie8-summary.aspx ). One of my favorites is the SmartScreen® Filter which helps people understand when they are about to visit a malicious site. There are other features visible and hidden that make getting malware onto a PC much more difficult.

A SmartScreen® display from IE 8

Additionally, if one attempts to open an attachment in a modern email program (such as Windows Live Mail) the malware file is blocked:

Much of the recent feedback has failed to take into account the ways that Windows 7 is better than Windows Vista at preventing malware from reaching the PC in the first place. In Windows 7 we have continued to focus on improving the ability to stop malware before it is installed or running on a PC.

The second issue to untangle is about the difference in behavior between different UAC settings. In Windows 7, we have four settings for the UAC feature: “Never Notify,” “Notify me only when programs try to make changes to my computer (without desktop dimming),” “Notify me only when programs try to make changes to my computer (with desktop dimming),” and “Always Notify.” In Windows Vista there were only two choices, the equivalent of “Never Notify” and “Always Notify.” The Vista UI made it difficult for people to choose “Never Notify” and thus choosing between extremes in the implementation. Windows 7 offers you more choice and control over this feature, which is particularly interesting to many of you based on the feedback we have received.

The recent feedback on UAC is about the behavior of the “Notify me only when programs try to make changes to my computer” settings. The feedback has been clear it is not related to UAC set to “Always Notify.” So if anyone says something like, “UAC is broken,” it is easy to see they are mischaracterizing the feedback.

The Purpose of UAC

We are listening to the feedback on how “Notify me only when…” works in Windows 7. It is important to bring in some additional context when explaining our design choice. We choose our default settings to serve a broad range of customers, based on the feedback we have received about improving UAC as a whole. We have learned from our customers participating in the Customer Experience Improvement Program, Windows Feedback Panel, user surveys, user in field testing, and in house usability testing that the benefit of the information provided by the UAC consent dialog decreases substantially as the number of notifications increases. So for the general population, we know we have to present only key information to avoid the reflex to “answer yes”.

One important thing to know is that UAC is not a security boundary. UAC helps people be more secure, but it is not a cure all. UAC helps most by being the prompt before software is installed. This part of UAC is in full force when the “Notify me only when…” setting is used. UAC also prompts for other system wide changes that require administrator privileges which, considered in the abstract, would seem to be an effective counter-measure to malware after it is running, but the practical experience is that its effect is limited. For example, clever malware will avoid operations that require elevation. There are other human behavior factors which were discussed in our earlier blog posts (post #1 and post #2).

UAC also helps software developers improve their programs to run without requiring administrator privileges. The most effective way to secure a system against malware is to run with standard user privileges. As more software works well without administrator privileges, more people will run as standard user. We expect that anyone responsible for a set of Windows 7 machines (such as IT Administrators or the family helpdesk worker (like me!)) will administer them to use standard user accounts. The recent feedback has noted explicitly that running as standard user works well. Administrators also have Group Policy at their disposal to enforce the UAC setting to “Always Notify” if they choose to manage their machines with administrator accounts instead of standard user accounts.

Recapping the discussion so far, we know that the recent feedback does not represent a security vulnerability because malicious software would already need to be running on the system. We know that Windows 7 and IE8 together provide improved protection for users to prevent malware from making it onto their machines. We know that the feedback does not apply to the “Always Notify” setting of UAC; and we know that UAC is not 100% effective at stopping malware once it is running. One might ask, why does the “Notify me only when…” setting exist, and why is it the default?

Customer-Driven Engineering

The creation of the “Notify me only when…” setting and our choice of it as the default is a design choice along the spectrum inherent in security design as mentioned above. Before we started Windows 7 we certainly had a lot of feedback about how the Vista UAC feature displayed too many prompts. The new UAC setting is designed to be responsive to this feedback. A lot of the recent feedback has been of the form of, “I’ll set it to ‘Always Notify,’ but ‘regular people’ also need to be more secure.” I am sure security conscious people feel that way, and I am glad that Windows 7 has the setting that works great for their needs. But what do these so called “regular people” want? How to choose the default, while honoring our secure design principles, for these people is a very interesting question.

In making our choice for the default setting for the Windows 7 beta we monitored the behavior of two groups of regular people running the M3 build. Half were set to “Notify me only when…” and half to “Always Notify.” We analyzed the results and attitudes of these people to inform our choice. This study, along with our data from the Customer Experience Improvement Program, Windows Feedback Panel, user surveys, and in house usability testing, informed our choice for the beta, and informed the way we want to use telemetry from the beta to validate our final choice for the setting.

A key metric that came out of the study was the threshold of two prompts during a session. (A session is the time from power up to power down, or a day, whichever is shorter.) If people see more than two prompts in a session they feel that the prompts are irritating and interfering with their use of the computer. In comparing the two groups we found that the group with the “Always Notify” setting was nearly four times as likely to have sessions with more than two prompts (a 1 in 6.7 chance vs a 1 in 24 chance). We gathered the statistic for how many people in the sample had malware make it onto their machine (as measured by defender cleaning) and found there was no meaningful difference in malware infestation rates between the two groups. We will continue to collect data during the beta to see if these results hold true in a much broader study.

We are very happy with the positive feedback we have received about UAC from beta testers and individual users overall. This helps us validate our “regular people” focus in terms of the trade-offs we continue to consider in this design choice. We will continue to monitor the feedback and our telemetry data to continue to improve our design choices on UAC.

So as you can see there is a lot of depth to the discussion of UAC and the improvements made in Windows 7 in UAC itself and in improving ways to prevent malware from ever reaching a PC. We are working hard to be responsive to the feedback we received from Vista to provide the right usability and security for people of all types. We believe we’ve made good progress and are listening carefully to the feedback on our UAC changes. Again please accept our most sincere thanks for the passion and feedback on Windows 7. While we cannot implement features the way each and every one of you might wish, we are listening and making a sincere effort to properly weigh all points of view. Our goal is to create a useful, useable, and secure Windows for all types of people.

Jon

User Account Control (UAC) – quick update

e7blog — Thu, 15 Jan 2009 11:00:00 GMT

There’s been a ton of interest in how we have improved user account control (UAC) and so we thought we’d offer a quick update for folks. We know most of you have discovered this and picked a setting that works for you, and we're happy with the feedback we've seen. This just goes into the details on the choice of defaults. --Steven

In an earlier blog post we discussed the why of UAC and its implications for Windows, the ecosystem, and our customers. We also talked about what we needed to do moving forward to address the data and feedback we’ve received. This blog post will provide additional detail on our response and what you can expect to see in the upcoming beta build in early 2009.

As mentioned in our previous post, and your comments supported this, the goals for UAC are good and important ones. User Account Control was created with the intention of putting you in control of your system, reducing cost of ownership over time, and improving the software ecosystem. It is important not to abandon these goals. Instead, we want to address feedback we’ve received and build on the telemetry we have using those to improve the overall experience without losing sight of the goals with which we agree.

For those of you using 6801 you have started to see the benefits of prompt reduction and our new and improved dialog designs. You also have seen our efforts to give the user greater control of their system – the new UAC Control Panel. The administrator now has more control over the level of notification received from UAC. Look for the UAC Control Panel to appear in Start Search, Action Center, Getting Started, and even directly from the UAC prompt itself. Of course, the familiar ways to access it from Vista are still present.

Figure 1: UAC Control Panel

The UAC Control Panel enables you to choose between four different settings:

Always notify on every system change. This is Vista behavior – a UAC prompt will result when any system-level change is made (Windows settings, software installation, etc.)
Notify me only when programs try to make changes to my computer. This setting does not prompt when you change Windows settings, such as control panel and administration tasks.
Notify me only when programs try to make changes to my computer, without using the Secure Desktop. This is the same as #2, but the UAC prompt appears on the normal desktop instead of the Secure Desktop. While this is useful for certain video drivers which make the desktop switch slowly, note that the Secure Desktop is a barrier to software that might try to spoof your response.
Never notify. This turns off UAC altogether.

We know from the feedback we’ve received that our customers are looking for a better balance of control versus the amount of notifications they see. As we mentioned in our last post we have a large number of admin (aka developer) customers looking for this balance, our data shows us that most machines (75%) run with a single account with full admin privileges.

Figure 2. Percentage of machines (server excluded) with one or more user accounts from January 2008 to June 2008.

For the in-box default, we are focusing on these customers, and we have chosen number 2, “Notify me only when programs try to make changes to my computer”. This setting does not prompt when you change Windows settings (control panels, etc.), but instead enables you to focus on administrative changes being requested by non-Windows applications (like installing new software). For people who want greater control in changing Windows settings frequently, without the additional notifications, this setting results in fewer overall prompts and enables customers to zero in on the key remaining notifications that they do see.

This default setting provides the right degree of change notification that a broad range of customers’ desire. At the same time we’ve made it easy and readily discoverable for the administrator to adjust the setting to provide more or fewer notifications via the new control panel (and policy). As with all of our default choices we will continue to closely monitor the feedback and data that come in through beta before finalizing for ship.

--UAC, Kernel, and Security program managers

User Account Control

e7blog — Wed, 08 Oct 2008 22:00:00 GMT

We promised that this blog would provide a view of Engineering Windows 7 and that means that we would cover the full range of topics—from performance to user interface, technical and non-technical topics, and of course easy topics and controversial topics. This post is about User Account Control. Our author is Ben Fathi, vice president for core OS development. UAC is a feature that crosses many aspects of the Windows architecture—security, accounts, user interface, design, and so on—we had several other members of the team contribute to the post.

We continue to value the discussion that the posts seem to inspire—we are betting (not literally of course) that this post will bring out comments from even the most reserved of our readers. Let’s keep the comments constructive and on-topic for this one.

FWIW, the blogs.msdn.com server employs some throttles on comments that aim to reduce spam. We don’t control this and have all the “unmoderated” options checked. I can’t publish the spam protection rules since that sort of defeats the purpose (and I don’t know them). However, I apologize if your comment doesn’t make it through. --Steven

User Account Control (UAC) is, arguably, one of the most controversial features in Windows Vista. Why did Microsoft add all those popups to Windows? Does it actually improve security? Doesn’t everyone just click “continue”? Has anyone in Redmond heard the feedback on users and reviewers? Has anyone seen a tv commercial about this feature?

In the course of working on Windows 7 we have taken a hard look at UAC – examining customer feedback, volumes of data, the software ecosystem, and Windows itself. Let’s start by looking at why UAC came to be and our approach in Vista.

The Why of UAC

Technical details aside, UAC is really about informing you before any “system-level” change is made to your computer, thus enabling you to be in control of your system. An “unwanted change” can be malicious, such as a virus turning off the firewall or a rootkit stealthily taking over the machine. However an “unwanted change” can also be actions from people who have limited privileges, such as a child trying to bypass Parental Controls on the family computer or an employee installing prohibited software on a work computer. Windows NT has always supported multiple user account types – one of which is the “standard user,” which does not have the administrative privileges necessary to make changes like these. Enterprises can (and commonly do) supply most employees with a standard user account while providing a few IT pros administrative privileges. A standard user can’t make system level changes, even accidentally, by going to a malicious website or installing the wrong program. Controlling the changes most people can make to the computer reduces help desk calls and the overall Total Cost of Ownership (TCO) to the company. At home, a parent can create a standard user account for the children and use Parental Controls to protect them.

However, outside the enterprise and the Parental Controls case, most machines (75%) have a single account with full admin privileges. This is partly due to the first user account defaulting to administrator, since an administrator on the machine is required, and partly due to the fact that people want and expect to be in control of their computer. Since most users have an Administrator account, this has historically created an environment where most applications, as well as some Windows components, always assumed they could make system-level changes to the system. Software written this way would not work for standard users, such as the enterprise user and parental control cases mentioned above. Additionally, giving every application full access to the computer left the door open for damaging changes to the system, either intentionally (by malware) or unintentionally (by poorly written software.)

Figure 1. Percentage of machines (server excluded) with one or more user accounts from January 2008 to June 2008.

User Account Control was implemented in Vista to address two key issues: one, incompatibility of software across user types and two, the lack of user knowledge of system-level changes. We expanded the account types by adding the Protected Admin (PA), which became the default type for the first account on the system. When a PA user logs into the system, she is given two security tokens – one identical to the Standard User token that is sufficient for most basic privileges and a second with full Administrator privileges. Standard users receive only the basic token, but can bring in an Administrator token from another account if needed.

When the system detects that the user wants to perform an operation which requires administrative privileges, the display is switched to “secure desktop” mode, and the user is presented with a prompt asking for approval. The reason the display is transitioned to “secure desktop” is to avoid malicious software attacks that attempt to get you to click yes to the UAC prompt by mimicking the UAC interface (spoofing the UI.) They are not able to do this when the desktop is in its “secure” state. Protected Admin users are thus informed of any system changes, and only need to click yes to approve the action. A standard user sees a similar dialog, but one that enables her to enter Administrative credentials (via password, smart card PIN, fingerprint, etc) from another account to bring in the Administrator privileges needed to complete the action. In the case of a home system utilizing Parental Controls, the parent would enter his or her login name and password to install the software, thus enabling the parent to be in control of software added to the system or changes made to the system. In the enterprise case, the IT administrator can control the prompts through group policy such that the standard user just gets a message informing her that she cannot change system state.

What we have learned so far

We are always trying to improve Windows, especially in the areas that affect our customers the most. This section will look at the data around the ecosystem, Windows, and end-users—recognizing that the data itself does not tell the story of annoyance or frustration that many reading this post might feel.

UAC has had a significant impact on the software ecosystem, Vista users, and Windows itself. As mentioned in previous posts, there are ways for our customers to voluntarily and anonymously send us data on how they use our features (Customer Experience Improvement Program, Windows Feedback Panel, user surveys, user in field testing, blog posts, and in house usability testing). The data and feedback we collect help inform and prioritize the decisions we make about our feature designs. From this data, we’ve learned a lot about UAC’s impact.

Impact on the software ecosystem

UAC has resulted in a radical reduction in the number of applications that unnecessarily require admin privileges, which is something we think improves the overall quality of software and reduces the risks inherent in software on a machine which requires full administrative access to the system.

In the first several months after Vista was available for use, people were experiencing a UAC prompt in 50% of their “sessions” - a session is everything that happens from logon to logoff or within 24 hours. Furthermore, there were 775,312 unique applications (note: this shows the volume of unique software that Windows supports!) producing prompts (note that installers and the application itself are not counted as the same program.) This seems large, and it is since much of the software ecosystem unnecessarily required admin privileges to run. As the ecosystem has updated their software, far fewer applications are requiring admin privileges. Customer Experience Improvement Program data from August 2008 indicates the number of applications and tasks generating a prompt has declined from 775,312 to 168,149.

Figure 2. Number of unique applications and tasks creating UAC prompts.

This reduction means more programs work well for Standard Users without prompting every time they run or accidentally changing an administrative or system setting. In addition, we also expect that as people use their machines longer they are installing new software or configuring Windows settings less frequently, which results in fewer prompts, or conversely when a machine is new that is when there is unusually high activity with respect to administrative needs. Customer Experience Improvement Program data indicates that the number of sessions with one or more UAC prompts has declined from 50% to 33% of sessions with Vista SP1.

Figure 3. Percentage of sessions with prompts over time.

Impact on Windows

An immediate result of UAC was the increase in engineering quality of Windows. There are now far fewer Windows components with full access to the system. Additionally, all the components that still need to access the full system must ask the user for permission to do so. We know from our data that Windows itself accounts for about 40% of all UAC prompts. This is even more dramatic when you look at the most frequent prompts: Windows components accounted for 17 of the top 50 UAC prompts in Vista and 29 of the top 50 in Vista SP1. Some targeted improvements in Vista SP1 reduced Windows prompts from frequently used components such as the copy engine, but clearly we have more we can (and will) do. The ecosystem also worked hard to reduce their prompts, thus the number of Windows components on the top 50 list increased. Windows has more of an opportunity to make deeper architectural changes in Windows 7, so you can expect fewer prompts from Windows components. Reducing prompts in the software ecosystem and in Windows is a win-win proposition. It enables people to feel confident they have a greater choice of software that does not make potentially destabilizing changes to the system, and it enables people to more readily identify critical prompts, thus providing a more confident sense of control.

One important area of feedback we’ve heard a lot about is the number of prompts encountered during a download from Internet Explorer. This is a specific example of a more common situation - where an application’s security dialogs overlap with User Account Control. Since XP Service Pack 2, IE has used a security dialog to warn users before running programs from the internet. In Vista, this often results in a double prompt – IE’s security dialog, followed immediately by a UAC dialog. This is an area that should be properly addressed.

Figure 4. Number of Microsoft prompters in the top 50 over time.

Impact on Customers

One extra click to do normal things like open the device manager, install software, or turn off your firewall is sometimes confusing and frustrating for our users. Here is a representative sample of the feedback we’ve received from the Windows Feedback Panel:

“I do not like to be continuously asked if I want to do what I just told the computer to do.”
“I feel like I am asked by Vista to approve every little thing that I do on my PC and I find it very aggravating.”
“The constant asking for input to make any changes is annoying. But it is good that it makes kids ask me for password for stuff they are trying to change.”
“Please work on simplifying the User Account control.....highly perplexing and bothersome at times”

We understand adding an extra click can be annoying, especially for users who are highly knowledgeable about what is happening with their system (or for people just trying to get work done). However, for most users, the potential benefit is that UAC forces malware or poorly written software to show itself and get your approval before it can potentially harm the system.

Does this make the system more secure? If every user of Windows were an expert that understands the cause/effect of all operations, the UAC prompt would make perfect sense and nothing malicious would slip through. The reality is that some people don’t read the prompts, and thus gain no benefit from them (and are just annoyed). In Vista, some power users have chosen to disable UAC – a setting that is admittedly hard to find. We don’t recommend you do this, but we understand you find value in the ability to turn UAC off. For the rest of you who try to figure out what is going on by reading the UAC prompt , there is the potential for a definite security benefit if you take the time to analyze each prompt and decide if it’s something you want to happen. However, we haven’t made things easy on you - the dialogs in Vista aren’t easy to decipher and are often not memorable. In one lab study we conducted, only 13% of participants could provide specific details about why they were seeing a UAC dialog in Vista. Some didn’t remember they had seen a dialog at all when asked about it. Additionally, we are seeing consumer administrators approving 89% of prompts in Vista and 91% in SP1. We are obviously concerned users are responding out of habit due to the large number of prompts rather than focusing on the critical prompts and making confident decisions. Many would say this is entirely predictable.

Figure 5. Percentage of prompts over time per prompt type.

Figure 6. Percentage of UAC prompts allowed over time.

Looking ahead…

Now that we have the data and feedback, we can look ahead at how UAC will evolve—we continue to feel the goal we have for UAC is a good one and so it is our job to find a solution that does not abandon this goal. UAC was created with the intention of putting you in control of your system, reducing cost of ownership over time, and improving the software ecosystem. What we’ve learned is that we only got part of the way there in Vista and some folks think we accomplished the opposite.

Based on what we’ve learned from our data and feedback we need to address several key issues in Windows 7:

Reduce unnecessary or duplicated prompts in Windows and the ecosystem, such that critical prompts can be more easily identified.
Enable our customers to be more confident that they are in control of their systems.
Make prompts informative such that people can make more confident choices.
Provide better and more obvious control over the mechanism.

The benefits UAC has provided to the ecosystem and Windows are clear; we need to continue that work. By successfully enabling standard users UAC has achieved its goal of giving IT administrators and parents greater control to lock down their systems for certain users. As shown in our data above, we’ve seen the number of external applications and Windows components that unnecessarily require Admin privileges dramatically drop. This also has the direct benefit of reducing the total amount of prompts users see, a common complaint we hear frequently. Moving forward we will look at the scenarios we think are most important for our users so we can ensure none of these scenarios include prompts that can be avoided. Additionally, we will look at “top prompters” and continue to engage with third-party software vendors and internal Microsoft teams to further reduce unnecessary prompts.

More importantly, as we evolve UAC for Windows 7 we will address the customer feedback and satisfaction issues with the prompts themselves. We’ve heard loud and clear that you are frustrated. You find the prompts too frequent, annoying, and confusing. We still want to provide you control over what changes can happen to your system, but we want to provide you a better overall experience. We believe this can be achieved by focusing on two key principles. 1) Broaden the control you have over the UAC notifications. We will continue to give you control over the changes made to your system, but in Windows 7, we will also provide options such that when you use the system as an administrator you can determine the range of notifications that you receive. 2) Provide additional and more relevant information in the user interface. We will improve the dialog UI so that you can better understand and make more informed choices. We’ve already run new design concepts based on this principle through our in-house usability testing and we’ve seen very positive results. 83% of participants could provide specific details about why they were seeing the dialog. Participants preferred the new concepts because they are “simple”, “highlight verified publishers,” “provide the file origin,” and “ask a meaningful question.”

In summary, yes, we’ve heard the responses to the UAC feature – both positive and negative. We plan to continue to build on the benefits UAC provides as an agent for standard user, making systems more secure. In doing so, we will also address the overwhelming feedback that the user experience must improve.

Ben Fathi