Network and potential malware

[Brodo_Swwaggins]

Hey everyone, 

I have a question regarding an issue with my network and potential malware. 

 

Today I lost my internet connection while watching netflix and playing civ 6. I initially tried, resetting the modem, my PC, and reconnecting the coax and ethernet cable to no avail. 

When I opened google Chrome I got redirected to a site that Chrome put up its warning signs against entering (sorry don't know the technical terms), like you do when you try and access a public wifi in an airport to the like. When I clicked through to the site i found the following:

The domain name was IP address/splash_offline.phb. (For security reasons i won't reveal the IP address). 

On the site was my ISP's name, a guide on what to do to restore connection and a link in the button called "Access to modem configuration". (I have attached an image but I'm afraid it's in Danish).

When I went to Firefox, I was again redirected to a site that said "Login to network" and the errorcode "mozilla_pkix_error_mitm". (SC attached)

I contacted my ISP and they said they knew nothing of it, and wanted to sent out a technician. I have never had any issues before, and Windows Defender has never produced any warnings. 

 

Does anyone have any idea on what going on and some good tips to what i should do?

 

Thanks from a Panicking Dane

[OddOod]

I know this is a really dumb question, but can you make sure the time is set correctly on your PC? 
It looks like firefox is saying the certificates aren't valid for your connection which can be cause by a corrupted cert store, in correct time on your device, or other things. 
What you are seeing when you get that splash_offline thing is the modem configuration page which seems to have a busted SSL certificate. 
My best guess is that your modem somehow corrupted itself, then a failsafe kicked in and reset to known-good factory settings. It's likely that tech will have to come out and reconfig it, unless customer service is willing to walk you through it over the phone

[Brodo_Swwaggins]

2 hours ago, OddOod said:

I know this is a really dumb question, but can you make sure the time is set correctly on your PC? 
It looks like firefox is saying the certificates aren't valid for your connection which can be cause by a corrupted cert store, in correct time on your device, or other things. 
What you are seeing when you get that splash_offline thing is the modem configuration page which seems to have a busted SSL certificate. 
My best guess is that your modem somehow corrupted itself, then a failsafe kicked in and reset to known-good factory settings. It's likely that tech will have to come out and reconfig it, unless customer service is willing to walk you through it over the phone

Thanks for the input, it turned out it was an issue with building electricity...out of all the things I thought was wrong hahah