Unable to Install Norton Security for Mac due to XPC authentication failure (-70605)

Console Log:

Mar 22 11:07:39  com.symantec.SymInstallHelper[910] <Notice>: SymXPC_Connection_Handler - got a connection 
Mar 22 11:07:39  com.symantec.SymInstallHelper[910] <Notice>: setPartnerPlistFile :/Applications/Install Norton Security.app/Contents/Resources/SymSupportFolder/com.symantec.partner.plist
Mar 22 11:07:39  com.symantec.SymInstallHelper[910] <Error>: Failed to authenticate installer package at path:/Applications/Install Norton Security.app/Contents/Resources/SymSupportFolder/Norton For Mac.mpkg.
	 Error Code:-70605
Mar 22 11:07:39  com.symantec.SymInstallHelper[910] <Notice>: Received an XPC cancel request. Quitting Helpertool

File Hash: 

$ openssl sha1 /Applications/Install\ Norton\ Security.app/Contents/Resources/SymSupportFolder/Norton\ For\ Mac.mpkg
SHA1(/Applications/Install Norton Security.app/Contents/Resources/SymSupportFolder/Norton For Mac.mpkg)= 107c60f87d5e4c5259970547f68209a25932c997

macOS Version: 10.15.3 (19D76)

Installer Version: 8.4.2f21 downloaded via norton.com/latestnsmac

You take care as well. 

Cheers

@SoulAsylum

Thank you for your advice!

I'm totally amazed a Windows professional has a passion to try to rescue a stupid, selfish macOS developer.

Anyway! Take care of yourself! (Especially from COVID-19!)

-Hewz

I found a workaround of this issue. The installer location of instruction below is

  • ~/Downloads/Install Norton Security.app
  1. Uninstall all Norton application and data by SymantecRemovalTool:
    ~/Downloads/Install Norton Security.app/Contents/Resources/SymantecRemovalTool
  2. Install SKU package:
    ~/Downloads/Install Norton Security.app/Contents/Resources/SymSupportFolder/Norton For Mac SKU.mpkg
  3. Install "core" package:
    ~/Downloads/Install Norton Security.app/Contents/Resources/SymSupportFolder/Norton For Mac.mpkg
  4. Restart your Mac
  5. Open Norton Security:
    /Application/Norton Security.app
  6. Start LiveUpdate
  7. Restart your Mac
  8. Open Norton Security then start LiveUpdate again
  9. Done!

My speculation:
XPC is an macOS interprocess communication technology that complements App Sandbox by enabling privilege separation. link
It's unknown how Norton devs uses XPC helper but I speculate they use it to verify the package version refer to their server's data (I didn't capture the packet but the app connects to the norton server when the installation starts. Also the contents of com.symantec.partner.plist is just version string.). Therefore its authentication would fail due to obsolete installer from http://norton.com/latestnsmac.
The issue I've been in trouble: https://community.norton.com/en/forums/norton-security-installation-failure seems to be the same reason.

Why so important to use the installer on http://norton.com/latestnsmac?
Just download it from your account page, you moron!:

I like automation using Automator script while create virtual machine, and I like to simplify its script. That's all.
I am going to modify my script to "evade" this problem.

My weekend's gone but happy to end :)

Hello. It appears you had this issue a few years ago, posted here in this thread. It was never resolved. Are you installing from an admin account on the computer? There may also be a region lock on the installer you are using, what is your current global region? Do you already have a Norton account where you can download your product from? Also have a look at this article.

Cheers