found a bunch of DO_NOT_TRUST_FiddlerRoot personal certificates installed on my system
Yes you should. In fact you should delete them. There's an adware that installs those certificates and injects encrypted HTML advertising content from various websites, hence SSL certificate.
To find more of your certificates:
Open mmc.exe --> crtl + M --> Certificates --> Click Add > --> My User account --> Click Finish --> Click OK
You also might want to run some or all of these:
- AdwCleaner
- Malwarebytes
- ComboFix
- CCleaner
- and finally an Anti-virus.
Update:
To make my answer more clear. If you have never installed Fiddler on your computer, chances are there's an Adware that installed the certificates.
From: https://www.telerik.com/fiddler/fiddlercore
What is Telerik FiddlerCore?
Progress® Telerik® FiddlerCore Embedded Engine is a .NET Class library you can integrate into your .NET Framework applications. There is also a .NET Standard 2.0 flavor of FiddlerCore that allows using it on any platform implementing .NET Standard.
Telerik FiddlerCore allows you to capture and modify HTTP and HTTPS traffic just like Fiddler, without any of the Fiddler UI.
Why Telerik FiddlerCore
Battle-tested code used by millions of users of the Fiddler application. Flexible licensing schemes for internal and public distribution. Ongoing support from the core development team. Key Features HTTP and HTTPS traffic capture and modification. Powerful object model for content filtering and modification. Store and reload web traffic. Support for virtually any client application. Support for most devices via mobile proxy settings.
Fiddler installs these certificates so it can capture and inspect encrypted Web traffic (for debugging).
In which case you should also check your Internet Proxy settings.
Additional links:
https://groups.google.com/forum/#!msg/httpfiddler/V7TXBlJch6Y/SgXN_tYy0-EJ;context-place=forum/httpfiddler
https://akhpark.wordpress.com/2014/03/17/whats-with-do_not_trust_fiddlerroot/