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Fixing the Unknown Publisher Warning for Authentic Software Deployment
If you are a software publisher or developer, then you must have dealt with the ‘Unknown Publisher Warning’ when running or distributing software. This alert pops up when an application does not have a valid digital signature from a trusted Certificate Authority.
Let’s understand what lies behind the “Unknown Publisher” warning and detailed methods for fixing it while also considering the potential security risks involved.
What is an Unknown Publisher Warning in Software Code Signing?
Unknown Publisher Warning Message is a protection alert that pops up when you try to install or run a program or software that has not been signed using a digital certificate like a code signing certificate or verified by a trusted software provider.
Here’s what an unknown publisher and a verified publisher look like:
The primary purpose of this pop-up message is to warn you regarding the security issues or concerns that you might face after installing or executing the program from an unknown publisher. The message indicates that the software/ app may contain malicious codes, like viruses and malware.
An unknown publisher is a software developer or organization that hasn’t confirmed their identity. If the identity is not verified, they don’t get recognized by operating systems like MacOS and MS Windows and web browsers like Google Chrome and Mozilla Firefox.
If you download an application from an unverified source, you will get the following warning:
If you still click on the Run option to proceed with the installation, you will come across a pop-up message once the software is downloaded.
Causes of Unknown Publisher Warning
It’s important for software vendors that users and operating systems trust their applications. If a software package triggers an “Unknown Publisher” warning, it raises security concerns and discourages users from proceeding with the installation. This section will cover the key reasons behind this warning.
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The file is from a source that is not digitally signed
If the software or file does not have a digital signature attached to it, Windows will label it as coming from an “Unknown Publisher.” This is common with files or programs that are homemade or downloaded from sources that don’t require or provide certificates.
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The certificate used to sign the file is expired, revoked, or invalid
Digital certificates are issued with an expiration date. If the certificate used to sign the file is expired or if the certificate authority has revoked it for any reason, Windows will not recognize it as valid. This will trigger the “Unknown Publisher” warning.
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The operating system does not recognize the publisher’s certificate
If the signing certificate is from a publisher that isn’t included in Windows’ trusted certificate authorities list, Windows will flag the file as coming from an “Unknown Publisher.” This could happen if the software were signed with a certificate from an untrusted authority.
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The file is from an untrusted or unknown source
Files downloaded from unknown or untrusted sources—such as suspicious websites, peer-to-peer networks, or email attachments—may not have Authenticode Signing. In such cases, Windows will warn the user that the file is from an unknown publisher to minimize the risk of installing potentially harmful software.
How to Fix Unknown Publisher Security Warning?
Both software developers or publishers and users face challenges when encountering the “Unknown Publisher” security warning. For developers, this warning can undermine trust in their software, while users may hesitate to proceed due to security concerns. Below are solutions tailored for both groups.
For Software Developers/Publishers
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Use Third-Party Tools for Digital Signing
For developers or software publishers, you can use third-party tools to sign your software, applications, source code, binary files, or firmware. Signing your software with a valid certificate can help avoid the “Unknown Publisher” warning. This method is useful if you are distributing software publicly or privately.
Here’s a quick look at how it works:
Step 1: Obtain a Digital Certificate
You can Buy code signing certificate from a recognized certificate authority (CA) such as DigiCert, Comodo, or Sectigo.
Step 2: Use Signing Tools
Tools like SignTool (available in Visual Studio) or OpenSSL can be used to sign your application digitally.
Step 3: Distribute Signed Software
After signing, distribute the software just as you would any other file. Users will no longer see the “Unknown Publisher” warning.
For Software Users
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Enable or Disable SmartScreen Filter
Windows SmartScreen is a security feature designed to protect your computer from malicious apps and websites. Sometimes, SmartScreen will flag applications from unverified publishers, causing the “Unknown Publisher” warning.
You can configure SmartScreen to allow trusted apps through. Keep in mind that disabling SmartScreen could expose your system to unnecessary risks. Always enable SmartScreen or set it to warn before bypassing the security measures.
Here’s how to manage SmartScreen settings:
- Open Windows Security (Search for “Windows Security” in the Start menu).
- Navigate to App & browser control.
- Under Reputation-based Protection, you can toggle SmartScreen settings. For example, you can choose to Warn instead of blocking the app or Turn off SmartScreen altogether (not recommended for general use).
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Bypass the Warning for Trusted Software
If you trust the publisher but the file is unsigned, or the certificate is expired, you can bypass the “Unknown Publisher” warning. You can use the way if you’re confident that the software is from a trusted source but lacks a valid signature. Here’s how:
- Right-click the file and select Properties.
- In the Properties window, look for an Unblock checkbox at the bottom.
- Check the box and click Apply, then OK.
- You should now be able to run the software without encountering the warning.
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Add the Publisher to Trusted Sources
If you frequently use software from a particular publisher and trust it, you can add that publisher to your list of trusted sources in Windows. It will help ensure that software from that publisher is always treated as safe by Windows. This method will prevent the “Unknown Publisher” warning from showing up for software from that publisher in the future.
To add a trusted publisher:
- Open the Microsoft Management Console (MMC) by typing mmc into the Start menu search and pressing Enter.
- In the MMC window, go to File > Add/Remove Snap-in.
- Select Certificates and click Add.
- Choose Computer Account and click Next, then Finish.
- Under Certificates (Local Computer), navigate to Trusted Root Certification Authorities.
- Right-click on Trusted Publishers and choose Import.
- Select the publisher’s certificate and follow the prompts to add it to the trusted list.
How Software Companies Can Verify Their Publisher Details After Signing?
After signing your software with a digital certificate, it is essential to run a quick check to verify the digital signature and timestamping. Here’s how you can check your signed program’s publisher details:
Step 1: Open the File Properties
Locate the signed .exe file and right-click on it. Select Properties to open the file details window. A window will open that looks like this:
Step 2: Locate the Digital Signature Tab
Click on the Digital Signatures tab at the top, the last option beside the Compatibility tab. The new window displays the sign of the signer, their email address, and the exact time and date when the software was signed via timestamping. Click on the Details option to proceed.
Step 3: View the Certificate Details
In the Details window, click on the View Certificate button to open a new window. This new window will provide more in-depth information about the certificate.
Step 4: Check the Subject Listing
In the Certificate Details window, locate the Subject field. This section should display your company name, verifying that the certificate is correctly linked to your organization.
Check that the details match your official business information as registered with the certificate authority.
Step 5: Verify Publisher Information
To confirm that your software is correctly signed and recognized as legitimate:
- Cross-check the certificate details with the Certificate Authority (CA) records.
- Test on different Windows systems to confirm that no unknown publisher warnings appear.
- Use Microsoft’s SignTool utility (signtool verify /pa yourfile.exe) to validate the signature and timestamp.
By performing these checks, you can verify that your software is properly signed, building trust and security for your users.
Difference Between Unverified and Verified Software Publisher
Your digital identity matters when you are in the digital space. It is a trusted way to prove to others that you are not an imposed. Similarly, if a software publisher wants to be trusted by the Windows operating system, they have to undergo a background check; when the process is complete, they will be given a code signing certificate. This signature confirms the authenticity of the publisher and ensures that the file hasn’t been altered since it was signed.
Now, how do you distinguish between verified and verified publishers? Let’s find out!
| Parameter | Verified Publisher | Unverified Publisher |
|---|---|---|
| Security risks | Authenticated by a trusted Certificate Authority (CA), ensuring that the software is from a legitimate and credible source. This validation significantly reduces the risk of downloading malware | Poses a greater security risk because of malware, spyware, or viruses, or may have been tampered with or come from untrustworthy sources. |
| Trust and credibility | Recognized as legitimate, and their identity is authenticated. This verification process ensures that the user can trust that the software is coming from the entity it claims to come from. | There is no assurance of their identity, which means there’s no clear confirmation about who is behind the software. |
| User Experience and Credibility | A smoother user experience which boosts credibility, increasing user confidence in the safety and quality of the software. | May trigger security warnings or be flagged as suspicious by the operating system, creating friction during installation. |
| Access to Extra Features | Has the ability to run advertising campaigns, access detailed analytics, or provide updates more easily, expanding their reach and improving user engagement. | May be restricted from accessing certain tools, features, or services, such as ad monetization programs, customer support, or detailed analytics. |
| Compliance | Publisher is compliant with industry standards, such as data protection laws (GDPR, CCPA, etc.) and security requirements. | May face challenges in terms of meeting industry regulations or compliance standards. |
| Phishing and fraud | Having their identity confirmed and validated, they help ensure that their content remains distinguishable from malicious copies or fake versions | Malicious actors can exploit unverified publishers to carry out phishing attacks or distribute fraudulent software. |
The Bottom Line
When you download or buy a software, you likely assume that they are safe. However, when an Unknown Publisher Warning message pops up on your screen, you quickly realize that’s not always the case. This is why it’s important to install software that comes from a verified publisher – and not from unverified or unknown. Similarly, for software developers and publishers, confirming that your software is properly signed with a valid digital certificate is essential to maintain trust and prevent security warnings.
Therefore, whether you are installing or distributing software, always prioritize security. Verify digital signatures, evaluate software sources, and understand the risks of bypassing security warnings to maintain system safety and trust.
