What is Unknown Publisher Warning?
Tags: webdev, beginners, devops, softwaredevelopment
Published: 2024-04-20 09:36:16

The unknown publisher warning is a security message that pops up when you try to install or run software from a source that Windows doesn't recognize or trust. It indicates that the publisher of the software has not been verified and could potentially be malicious. Heeding this warning can help protect your computer from malware.

## What Triggers the Unknown Publisher Warning?

The unknown publisher message appears when attempting to install or launch software that originates from a source outside of the standard Windows repositories. 

Here are some examples of when you may encounter this warning:

---> Downloading and running an executable file (.exe) from an unknown website. Windows can't verify the identity of the publisher.

---> Installing software that isn't digitally signed by the developer. Unsigned apps don't validate the source.

---> Opening a non-store app on Windows 8/10. Only Microsoft Store apps are recognized as trusted.

---> Running an app that was blocked by Windows Defender SmartScreen. This indicates it may be malicious.

---> Executing software from a disc or external drive. The origin is unclear.

---> Enabling an unsigned system driver. Drivers should be digitally signed by the OEM.

Essentially, anything that is not from the Microsoft Store or a major commercial software provider may trigger the warning. It is a protective measure to avoid potentially harmful software from unknown publishers.

## Is the Software Safe to Run?

The unknown publisher warning does not necessarily mean the software is malicious - it simply means the developer and distribution source have not been verified. However, dismissing the warning and running software from untrusted sources is risky:

---> **It could be malware -** false positives are rare. Most malware comes from unverified publishers.

---> **It bypasses security checks -** SmartScreen and antivirus can't screen unverified apps. This leaves you vulnerable.

---> **Less recourse if something goes wrong -** untrustworthy publishers won't provide support if their software damages your system.

---> **It makes you prone to future attacks -** dismissing the warning repeatedly will train you to run risky software.

While the software may sometimes be legitimate, running it essentially disables your system's primary defenses against malware. You should avoid dismissing the warning without verifying the publisher first.

## How to Verify Software Safety

If you have a legitimate need to run software that triggers the unknown publisher warning, you can take steps to validate it first:

---> **Check reviews -** research the software and see if trusted sources have recommended it. Look for professional reviews.

---> **Scan for malware -** use your antivirus to scan the install file before running it. This can detect known threats.

---> **Assess the publisher -** visit the software company's website to confirm they are real and trustworthy. Avoid amateur sites.

---> **Only download from official sources -** don't use third-party download sites, as they could have tampered with the software.

---> **Check digital signatures -** legitimate software may be unsigned but not malicious. You can inspect it for valid digital signatures.

---> **Use VM first -** test the software in a virtual machine sandbox before installing it locally. This isolates any threats.

---> **Contact the publisher -** if possible, contact the developer directly to confirm the software's authenticity.

While tedious, taking these precautions can give you reasonable assurance that the software is not malicious. You should only bypass the warning if your research reliably indicates the publisher and app are safe.

## How to Add a Publisher to Trusted List

Once you have verified an unknown publisher, you can add them to the trusted publishers list. This will prevent the warning from appearing for software from that source in the future:

**On Windows 8 and 10:**

---> Launch the software which triggers the warning.

---> Click "More info."

---> Select "Run anyway."

---> Check the "Always trust software from ???Publisher name???" box.

---> Click "Yes."

This will add the publisher to the trusted list stored in the registry. Their apps will now launch without the warning.

**On Older Versions of Windows:**

---> Right-click the app shortcut or exe.

---> Choose "Properties."

---> Select the "Digital Signatures" tab.

---> Click "Details" and then "View Certificate."

---> Click "Install Certificate".

---> Select "Local Machine" and click "Next."

---> Place it in the "Trusted Publishers" certificate store.

Future software installs and launches from this publisher will no longer trigger the unknown publisher warning. However, only add publishers after verifying their trustworthiness.

## Consequences of Ignoring the Warning

Bypassing the unknown publisher warning repeatedly can make your device increasingly vulnerable to malware. Potential consequences include:

---> Malware or virus infection - the biggest risk. Malicious software can damage your system, steal data, encrypt files for ransom, etc.

---> Spyware installation - malicious programs that record your activities and transmit private data.

---> Trojan horses - malware disguised as legitimate software that gives attackers system access.

---> System instability - untrusted apps can interfere with properly functioning system software and settings.

---> Performance issues - malware and untrusted software may consume excessive resources, slowing down your PC.

---> Credential theft - rogue apps can steal login details, financial information, and other sensitive data.

---> Lost data - some malware deletes or encrypts your personal files.

Ignoring the unknown publisher warning exponentially increases your exposure to such threats compared to running only trusted software. Make certain to validate unfamiliar publishers before enabling their software.

## Frequently Asked Questions

**Why do I get the warning for some downloaded programs but not others?**
You'll only see the unknown publisher warning for software that originates from outside the Windows Store or the major commercial developers. Apps from Microsoft, Adobe, etc. won't trigger it because they are recognized trusted publishers.

**Can I disable the warning?**
It is possible to disable SmartScreen, which generates many of the warnings. However, this will leave you completely vulnerable to untrusted software, so it is strongly discouraged.

**What if anti-malware scanners find nothing wrong with the software?**
Malware scanners rely on recognizing known threat signatures. New zero-day malware often goes undetected. Lack of detections does not guarantee the software is safe.

**How can valid software be signed by the publisher?**
Software vendors can get digital certificates to cryptographically sign their apps. Signed executables will not generate the unverified publisher warning.

**Can I Fix Unknown Publisher Security Warning in Windows 10?**
Yes, you can [fix unknown publisher security warning message in Windows 10](https://sslinsights.com/fix-unknown-publisher-security-warning-windows-10/). 

Follow these: 

Go to Windows Security settings and allow the app through Controlled Folder Access. You can also turn off reputation-based protection in Virus & Threat Protection settings.

**Can I get the developer to sign their software after the fact?**
Usually not. Applying digital signatures is done at software compile time by the publishers. Users generally cannot sign unsigned apps themselves.

**Will Windows Defender SmartScreen bypass the warning itself?**
No. SmartScreen will continue to flag unverified publisher files as potentially dangerous. You have to manually inspect and allow the apps.

The unknown publisher warning exists to protect you from running software that could potentially harm your device or compromise your privacy and security. While occasionally inconvenient, it should not be dismissed without first verifying the legitimacy of the app through research and scanning. Adding publishers to the trusted list also requires advance confirmation of their trustworthiness. Following security best practices will help ensure this important safeguard continues working to keep your system malware-free.