What is this file that repeatedly re-installs itself and why is it trusted by Norton

The details of a file installation identified by Norton Insight is pasted below.

Why is this file trusted when there are so few Norton users (less than 5)?  Do you know who is installing this on my computer without my permission and knowledge?

When I rename it or delete it, it gets re-installed somehow.  Sometimes it makes the folder in which it is installed inaccessible by me, on my own computer, with full administrative rights, after I rename it or look at it with the “locate” button in the File Insight popup.

I have never knowingly requested or installed a content decryption module and have no idea what this is for.  It seems rather suspicious.  I wonder if it is a tool for someone to acquire information from my computer.

Do you have any more information on it?

Thanks.

- Sveinn

Filename: widevinecdmadapter.dll

Full Path: c:\Users\Sveinn\AppData\Local\Google\Chrome\User Data\WidevineCDM\1.4.8.823\_platform_specific\win_x86\widevinecdmadapter.dll

Developers 

Google Inc

Version 

44.0.2403.125

Identified 

7/31/2015 at 8:39:01 AM

Last Used 

Not Available

Startup Item 

No

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Very Few Users

Fewer than 5 users in the Norton Community have used this file.

Very New

This file was released less than 1 week  ago.

Trusted

Norton has given this file a trusted rating.

____________________________

Source File:

chrome.exe

File Created:

widevinecdmadapter.dll

____________________________

File Thumbprint - SHA:

1fcd5ff6b9ce7977c3bef61d44e69fff58f5a31dacfa8cd49494d8e0dc401b04

File Thumbprint - MD5:

Not available