I have put together a bare-bones test case which literally does nothing but FiddlerApplication.Startup(8877, true, true); and even with this after clearing the personal store of FiddlerRoot.cer, i'm getting a bunch of random FiddlerRoot.cer sometimes as many as 10 instantly being inserted into the current users personal store. Here is a screenshot of what happens when running the test case and refreshing a web page.
Ultimately it causes Fiddler to spam the error below to my log output:
(20/06/2014 00:43:37)[LogString]/Fiddler.CertMaker> Invoking makecert.exe with arguments: -pe -ss my -n "CN=p.midasplayer.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha1 -m 132 -b 06/19/2013
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(20/06/2014 00:43:37)[LogString]/Fiddler.CertMaker>8-CreateCert(p.midasplayer.com) => (-1)
Results from C:\Users\Spark\AppData\Local\Test\MakeCert.exe -pe -ss my -n "CN=p.midasplayer.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha1 -m 132 -b 06/19/2013
Error: There are more than one matching certificate in the issuer's my cert store
Failed