Malware infection not detectable and issue resetting windows 10 to correct malware issue

[colederrib]

Hello,

My apologies in advance if this has been asked before. Recently I got a new laptop. I was using ESET antivirus / firewall on it. Somehow a family member manged to get it infected with some type of malware. This program locked up the browser in question and began to play an audible alert indicating the system was infected with a virus and to call a toll free number. Thankfully I'm a bit too experienced to fall for that one. Rebooting the system did nothing to solve the issue. Other browsers would function just not the one where this malware had taken hold.

My initial thoughts are always nuke from orbit when faced with a virus however I figured I'd try a few scans first. A scan using eset detected nothing. I downloaded and installed malwarebytes and ran a scan from there which also detected nothing. At this point I decided to proceed with a redo and initiated a reset using the windows 10 built in reset function. I chose to remove all files. The reset completed but with an error indicating that not all personal files could be removed (I'm still looking into this matter). A second attempt with a full reset and drive clean failed to do anything (actually had an error that nothing was done). I've created a windows 10 DVD for my next attempt but before I get there...

Did the initial reset have any chance of wiping out the infection? I can't decide if I trust it which translates to I don't. Any suggestions for what might have been able to detect this malware (if anything).

This laptop came preinstalled with windows 10 but it must be a custom image as its got some norton products wanting to run as part of the base install (not gonna happen) but the software is there even on a reset. Would using a Windows 10 disk created using another system allow me to get windows 10 onto the laptop without having the unwanted bloatware that came with the initial setup?

Would you trust a reset that failed to remove some personal files to have cleaned the infection?

I realize I'm all over the place with this and I will try to clarify any points as needed.

Thank you,



UPDATE: I've managed to get the system to clean the drives so I'm reasonably sure that I'm good. I'd still love a though on what the malware could have been and how I could have detected it. I'm still worried it got past my security without so much as a notification and became undetectable after that.

 

[itsVance]

Hello colederrib, sorry to hear you are a victim of malware. What you were facing was an attempt at a randsomware infestation. If you had called the #, it would likely had resulted in them charging you to fix the computer and once you let them in, they would encrypt your files and demand that you pay them even more.

If you chose the reset option that resets all system files, and you also had a virus with the ability to reinstall itself, the reset would likely have removed its means of self installation. If you had infected personal files, its possible to get reinfected once you access those files.

Some viruses infect your boot sector, in which case when you do a full reset on your PC; you should make sure to rewrite your boot sector as well.

I hope this has the answer your looking for.