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Norton reports this update has 'Trojan.GEN.2' and blocks the installation.
Here is the clean scan of the CDExPortable_1.84_online.paf.exe online installer: https://www.metadefender.com/#!/results/file/ZTE3MDQyMFMxTEl2TTc4QWxIeXY...
Here is the clean scan of CDex which is downloaded during installation: https://www.metadefender.com/#!/results/file/ZTE3MDQwN3IxMTVMMzRhZ0JrWVB...
As you can see all antivirus engines show both as clean. Your current version of Norton is showing a generic notification. It hasn't found a trojan, it found what its engine thinks could be a possible generic trojan. You'll have to submit a false positive report and wait for them to fix their error.
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