We have Windows application (MSI install package), downloadable from our site. The problem is, that browsers and 3rd party antiviruses prevent some users from download an APP. Is there a way to make our MSI package more trustable for browsers and antivirus? Maybe it can be checked and uploaded in some other resource, and downloadable for users from here?
P.S. We use code signing certificate, and Windows store is not a variant for us now.
Reputable anti-virus vendors have a way you can send your installation packages to be "whitelisted". Browsers have their own heuristics and using an EV certificate (more expensive) is supposed to help. Edge also supposedly respects the Defender whitelist.
Ultimately, the more downloads you get, the better your URL's reputation, the better you pass the heuristics.
We've been building and releasing the same application for almost 20 years and AV false positives can still create problems. This is how we do it today:
After each release, we scan our new setup on https://www.virustotal.com/gui/home/upload and if we notice any AV vendors flagging it we reach out to each of them and submit a request for false positive removal. They all have some form or email address where you can contact them.
They usually process these requests in a few days, so no real big problem for our users and doesn't take a lot of time.
Now, with SmartScreen, there is another story. Even if our package was digitally signed for over a decade, 2 years ago when we renewed our certificate Windows flagged our installer for about 2-3 months.
This was an installer with hundreds of thousands if not millions of users in the last decade. In the end, its reputation system got back to normal and stopped flagging it but it was really annoying for our customers.
The solution to this is to buy an EV certificate (confirmed by some of our customers) and then you will get an instant reputation with SmartScreen. This Spring our normal certificate expires and we will go the EV route too.
You can read more about digital signing and EV certs in the following articles:
Why EV Code Signing? EV Code Signing vs. Regular Code Signing
How to avoid the "Windows Defender SmartScreen prevented an unrecognized app from starting" warning
I am working for a remote client (They're in US and we're in Canada) and we are developing a Windows client. We are going to have them purchase an EV certificate so we can digitally sign the app.
We've done this in the past with non-EV certificated but from what I've read, EV certificates keys come on a physical USB device. I contacted ComodoSSL to see if we can get more than one as I see there being a big risk (And cost) for shipping the key back and forth. They said that can only issue one.
I will be the only one using the key to sign the app but I don't feel comfortable with the client not having a backup.
I'm sure I'm not the only one to have run into this situation and was looking for some feedback as to how others handle this without purchasing an HSM?
My company distributes an installer to customers via our website. Recently when I download via the website and try to run the installer I get the warning message:
Windows protected your PC
Windows Defender SmartScreen prevented an
unrecognized app from starting. Running this app might put your PC at
risk.
If I right-click on the installer and choose Properties I note the following:
Our installer is signed.
How do I find the reason for the Windows Defender SmartScreen warning?
I have not managed to find any log file for Windows Defender nor found anything in the Event Viewer.
TL;DR
This warning is shown if your app doesn't have enough reputation with Microsoft SmartScreen yet. In order to gain reputation, you can either
submit your app for malware analysis to Microsoft,
buy an "Extended Validation" code signing certificate,
buy a standard code signing certificate, or
just wait for a long time.
Read on for the details about these different options.
Option 1: Submit your app for malware analysis to Microsoft
Microsoft allows software developers to submit a file for malware analysis. According to Microsoft, this will help developers to "validate detection of their products". If the review was successful, the Microsoft SmartScreen warnings will go away faster, or sometimes even instantly (it worked instantly for one of my own apps). You need to have a Microsoft account to submit your app for review.
However, note that if you release an updated version of your app, then you'll also have to request a new review again. To overcome this problem, you'll either have to use an "Extended Validation" or a standard code signing certificate (see below).
Option 2: Buy an "Extended Validation" code signing certificate
A guaranteed way to immediately and permanently get rid of the Microsoft SmartScreen warnings is to buy an "Extended Validation" (EV) code signing certificate from one of the Microsoft-approved certificate authorities (CA's), and to sign your app with that EV certificate.
Such an EV certificate will cost you somewhere between 250 and 700 USD per year, and will only be issued to registered businesses. If you're a single developer, you must be a sole proprietor and have an active business license. You can read more about the formal requirements for EV code signing certificates in the EV Code Signing Certificate Guidelines.
An EV certificate will typically be shipped to you by physical delivery on a hardware token.
Option 3: Buy a standard code signing certificate
You can also buy a cheaper "standard" (i.e. non-EV) code signing certificate, and sign your app with that certificate. This will also permanently, but not instantly, make the Microsoft SmartScreen warnings disappear. Standard code signing certificates will cost you between 100 and 500 USD per year, and can also be issued to private developers without an active business license. Some CA's also offer discounts for open source projects.
No instant solution
The problem with standard code signing certificates is that they do not instantly silence Microsoft SmartScreen. Instead, some time will be needed for your certificate to build reputation before the warning will go away. However, once your certificate has built enough reputation, all applications signed with that certificate will be permanently trusted by Microsoft SmartScreen and won't trigger the warning anymore.
How long will it take?
So, how long will it take until the Microsoft SmartScreen warning will disappear when using a standard code signing certificate? Unfortunately, this is difficult to answer, since Microsoft itself refuses to publish any details about this. According to inofficial numbers reported by various sources (see below), it usually takes between 2 and 8 weeks until the warning will permanently go away. It seems that the exact duration also depends on the reputation of the website from which your app is downloaded.
The inofficial numbers are:
18 days and about 430 app installs. Source: one of my own certificates (Dec 2022)
42 days and about 1.400 app installs. Source: one of my own certificates (Feb 2021)
16 days and about 2.000 app installs. Source: one of my own certificates (May 2020)
One month and more than 10.000 downloads. Source: here (Jan 2020)
Between a few weeks and a month. Source: here (Dec 2019)
About 2-3 weeks. Source: here (Dec 2019)
About 3.000 downloads. Source: here (Dec 2013)
The problem of certificate rollover
Certificate rollover occurs when your old certificate expires and you begin signing your code with a renewed certificate.
It's a good idea to buy your standard code signing certificate with the longest possible validity period because when you renew your certificate, the reputation will unfortunately not automatically carry over to the renewed certificate (not even if it's signed against the same private key as the old certificate).
However, you can mitigate the rollover problem by getting your renewed code signing certificate before your old certificate expires, and then using both the old (but not yet expired!) and the renewed certificate to sign your code, resulting in two signatures. The signature from your old certificate will continue to bypass SmartScreen and, at the same time, the new signature will help the new certificate to build up trust. So, the idea is that your new certificate becomes trusted before your old certificate expires.
If your old certificate should already have expired, then you can (and should!) still add the signature from your renewed certificate to an already released version of your app, in order to gain reputation for the renewed certificate.
To correctly dual-sign your app, first sign your code with the old certificate, and then sign it again with the renewed certificate, using the /as command line option of Microsoft's SignTool to append an additional signature to the first one (instead of replacing it).
Option 4: Just wait for a long time
If you don't take any measures at all, the Microsoft SmartScreen warning will also go away eventually. This might however take a ridiculous amount of time (months) and / or downloads (tens of thousands). Another big problem is that each time you'll release an updated version of your app, the waiting period will start all over again. So, this probably isn't the solution you're looking for.
After clicking on Properties of any installer(.exe) which block your application to install (Windows Defender SmartScreen prevented an unrecognized app ) for that issue i found one solution
Right click on installer(.exe)
Select properties option.
Click on checkbox to check Unblock at the bottom of Properties.
This solution work for Heroku CLI (heroku-x64) installer(.exe)
If you have a standard code signing certificate, some time will be needed for your application to build trust. Microsoft affirms that an Extended Validation (EV) Code Signing Certificate allows us to skip this period of trust-building. According to Microsoft, extended validation certificates will enable the developer to immediately establish a reputation with SmartScreen. Otherwise, the users will see a warning like "Windows Defender SmartScreen prevented an unrecognized app from starting. Running this app might put your PC at risk.", with the two buttons: "Run anyway" and "Don't run".
Another Microsoft resource states the following (quote): "Although not required, programs signed by an EV code signing certificate can immediately establish a reputation with SmartScreen reputation services even if no prior reputation exists for that file or publisher. EV code signing certificates also have a unique identifier which makes it easier to maintain reputation across certificate renewals."
My experience is as follows. Since 2005, we have been using regular (non-EV) code signing certificates to sign .MSI, .EXE and .DLL files with timestamps, and there has never been a problem with SmartScreen until 2018, when there was just one case when it took 3 days for a beta version of our application to build trust since we have released it to beta testers. It was in the middle of the certificate validity period. I don't know what SmartScreen might not like in that specific version of our application, but there have been no SmartScreen complaints since then. Therefore, if your certificate is a non-EV, it is a signed application (such as an .MSI file) that will build trust over time, not a certificate. For example, a certificate can be issued a few months ago and used to sign many files, but for each signed file you publish, it may take a few days for SmartScreen to stop complaining about the file after publishing, as was in our case in 2018.
We didn't submit our software to Microsoft malware analysis. Microsoft started to provide this service in 2017. It may be a viable alternative to an Extended Validation (EV) certificate.
In conclusion, to avoid the warning altogether, i.e., prevent it from happening even suddenly, you need an Extended Validation (EV) code signing certificate, and/or, you can submit your software to Microsoft malware analysis.
UPDATE: Another writeup here:
How to add publisher in Installshield 2018
(might be better).
I am not too well informed about this issue, but please see if this answer to another question tells you anything useful (and let us know so I can evolve a better answer here): How to pass the Windows Defender SmartScreen Protection? That question relates to BitRock - a non-MSI installer technology, but the overall issue seems to be the same.
Extract from one of the links pointed to in my answer above: "...a certificate just isn't enough anymore to gain trust... SmartScreen is reputation based, not unlike the way StackOverflow works... SmartScreen trusts installers that don't cause problems. Windows machines send telemetry back to Redmond about installed programs and how much trouble they cause. If you get enough thumbs-up then SmartScreen stops blocking your installer automatically. This takes time and lots of installs to get sufficient thumbs. There is no way to find out how far along you got."
Honestly this is all news to me at this point, so do get back to us with any information you dig up yourself.
The actual dialog text you have marked above definitely relates to the Zone.Identifier alternate data stream with a value of 3 that is added to any file that is downloaded from the Internet (see linked answer above for more details).
I was not able to mark this question as a duplicate of the previous one, since it doesn't have an accepted answer. Let's leave both question open for now? (one question is for MSI, one is for non-MSI).
I distribute a Windows desktop app which has all executable files digitally signed by a Verisign Class 3 Code Signing certificate. For the vast majority of users, this seems to work fine.
However a small number of users report the certificate is invalid. They say it comes up with the message "A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider". This corresponds to error code CERT_E_UNTRUSTEDROOT (0x800B0109). This has also been reported on a fully-updated Windows 7 machine. So presumably my certificate is OK, but Windows sometimes doesn't trust VeriSign certificates.
Why does Windows sometimes not trust VeriSign? Is there anything I can add to my installer (also signed) which will tell Windows to trust the certificate?
There are frequent updates of the Root Certificates which Microsoft rolls out via Windows Update, but which are tagged as "optional update". Hence not all users may have them installed and may need to install them manually. This also holds for "fully updated" machines, as the automatic installation is often set to only install "important updates", which the Root Certificate updates are not.
Depending on the type of desktop application, you may have to follow certain rules when signing, too. For example applications interacting with the Windows Security Center require essentially the same signing method as drivers. That is, the certificate chain gets embedded along with the signature (/ac switch to signtool). You can get the MSCV-VSClass3.cer applicable to VeriSign certificates here.
The process is often called cross-signing, which seems to be a misnomer. While this is one step in getting your driver binary or catalog cross-signed, the vital step is that Microsoft signs the driver (or more usually the catalog file these days), which is the actual cross-signing.
We offer a Windows program downloadable as an InstallShield EXE from our website.
When someone running IE9 attempts to download and run our software, they see the following message at the bottom of their screen:
PROGRAMNAME.exe is not commonly downloaded and could harm your computer.
[DELETE] [ACTIONS] [VIEW DOWNLOADS]
I've read http://blogs.msdn.com/b/ie/archive/2011/03/22/smartscreen-174-application-reputation-building-reputation.aspx
It suggests:
Digitally sign your programs with an
Authenticode signature.
Ensure downloads are not detected as
malware.
Apply for a Windows Logo.
We've done all three things. Our EXE is digitally signed with an authenticode signature (and the bar above the warning message is orange, not red, indicating that IE9 recognized and verified the signature). Our download is not detected as malware by any antivirus program we've tried. And we have applied for and received a Windows Logo.
As yet, most of our customers are not using IE 9. But this is very troublesome to those who do. Is there anything else we can do about this, or do we just have to wait until a critical mass of customers have downloaded this software before this message will go away?
(Does that mean when we release a new version, all IE 9 users will get this message again until enough of them have downloaded it?)
UPDATE 2011-06-14:
Thanks, #EricLaw-MSFT. URL is http://dakim.dakiminc.netdna-cdn.com/DakimBrainFitness.exe . (It's found on the "Download Free Trial" button on http://www.dakim.com .)
We've only been offering downloadable trials for a short while. Our primary distribution method is installation DVDs.
Extended Validation Code Signing Certificates don't suffer from the need to build reputation slowly according to this post:
Reputation is generated and assigned to digital certificates as well as specific files. Digital
certificates allow data to be aggregated and assigned to a single certificate rather than many
individual programs. Although not required, programs signed by an EV code signing certificate can immediately establish reputation with SmartScreen reputation services even if no prior reputation exists for that file or publisher. EV code signing certificates also have a unique identifier
which makes it easier to maintain reputation across certificate renewals. Only Authenticode
Certificates issued by a CA that is a member of the Windows Root Certificate Program can establish
reputation.
At this time, Symantec and DigiCert are offering EV code signing certificates.
In an effort to improve my answer, I've added a link to a similar question I asked and eventually answered myself.