Possible virus infestation

[raksar]

Hi.
A few months ago I had given my laptop to a friend to play some games and turns out, he was streaming shows from streaming websites as well. He might have clicked on something and I think I have a virus infestation because last week I found out that I had a bitcoin miner in my laptop. I was able to get rid of it but a few days ago I found some other problems as well.
1. There is a safe search bar in my Firefox browser which I am not able to remove. I had it in chrome and I thought that only chrome was infected but turns out it's also there in Firefox.
2. A few minutes ago I had a GB of data which went missing from one of my partitions in the HDD. I'm not able to figure out what data went missing as I don't know how to track HDD activities.

Please help. I want to remove the safe search bar from my browsers and the computer itself. I also want to know if there is a possibility of a virus being the reason of my files getting deleted. If that's the case then how do I get rid of both the problems?

Information on my laptop:
Windows 8.1 pro (64bit)
Intel core i7-3rd generation
1TB HDD
2GB Radeon graphics (7700M)
8GB RAM

For keeping a check on invaders I use:
1. Windows defender
2. CCleaner for registry cleaning.

Please help.

 

[COLGeek]

MERGED QUESTION
Question from raksar : "Virus in my computer? Multiple problems"

HI. I have a laptop and recently I had given it to my friend so that he could play some games on it. With that he was also watching shows from streaming websites. My guess is that he must have clicked something wrong because I found that I had a bit coin miner in my computer. I was able to successfully remove that but there are two or three different problems that I'm not able to sort out. These are follows:
1. I have a secure search bar on my mozilla Firefox browser. I had it in Google Chrome as well but I thought that only chrome was infected. Turns out it's pretty much happening in Firefox and Internet Explorer as well.
2. Just a few minutes ago I realised that I had a GB of data missing in one of my partitions. I haven't deleted anything from it so there shouldn't be a GB missing in it. How did that data disappear?

I want to remove that secure search bar from my computer because I'm certain that it's a virus. Regarding the hard drive data missing, I'm completely lost. Does anyone have an idea as to what might be the problem?

I use:
Windows 8.1 pro (64 bit)
Intel i7-3rd generation with 1TB HDD
2GB Radeon 7700M series
8GB RAM.
For security I use Windows Defender.
For registry cleaning I use CCleaner.

Please help.

 

[COLGeek]

Please ask a question a single time, in a single section of the forum. Use tags to expand the topic as needed. Thank you.

 

[JoshRoss]

From what I can tell, it looks like system wide adware and a browser hijacker. Not surprising at all, free streaming websites do that more than often. Try simple conventional steps below to take care of your issue. If it doesn't help, we will go more thorough.

1. Check your browser for any add-ons or extensions you do not recognize and remove them.
2. Check your installed programs and see if there isn't anything suspicious that was installed lately (If there is, simply remove them).
3. Install any popular antivirus and do a quick scan (Majority of the providers do have free versions of their software). Or just use Windows Defender. It works really well in most cases.
4. Install and scan your PC with Malwarebytes and Hitman Pro to clean most adware.

 

[raksar]

Thanks a lot Josh for your quick reply. I will scan everything today and will let you know about my results tomorrow at the same time.

Thanks.

 

[raksar]

Thanks a lot Josh, turns out that everything has been solved. I will definitely be careful the next time. Followed your steps and the issues have been resolved. Thanks a lot.

 

[JoshRoss]

I am glad you got that sorted out! If you need any more help, let me know, I will gladly help you resolve the issue!

Some advice: Make sure you have some form of adblock (uBlock is good) to deny ad-spread malware and annoying ads in general.

 

[raksar]

Hi Josh,
I have followed your steps and added the extension which blocks unwanted stuff from the internet. Your solution was excellent and up to the point.

Thanks a lot!