My isp Hijacked my homepage

Hello.Just a few moments ago when i started my PC ,open the browser instead of my home page (google.ro) i've got this (see image).It's an advertising of one of My ISP new services.
How did they do it?Would open DNS prevented this?
I'm not very experienced when it comes to privacy.

 

Noroc!
It seems that you're using Firefox.
What is in Edit->Preferences->Main->Home Page ?
If there is google.ro then try open a new page and specifically enter the url http://google.ro if it doesn't open then probable the url is hijacked on the way.
You can try to ping google.ro and see what you get.

 

Multumesc
This was a one time incident.After i restarted Firefox it reverted back to google.ro.
After i opened IE and Opera Portable and the homePage was not changed.The homepage always was the same http://www.google.ro/,the ping looks ok to me.I'm more interested about preventing this in the future.
I know they are watching ,but to do this for advertising is not ok with me

 

To answer your question, yes, OpenDNS would prevent this.

 

Not always, if you're not using https the page transfered to you can be tampered by man in the middle, and your isp is in the middle, it can take google page you requested and modify it so it redirects to their page (or opens a pop-up to their page)

 

As far as I'm aware, this is actually illegal, as it's a form of hacking, and would go against nearly all ISP's abuse rules.

 

Faking DNS is also hacking so I don't see a big difference from practical point of view.

 

Actually it's not. They can divert failed pages/searches/etc all they want.

 

Thanks all for the replies.It's more clear now.Around here one gets away with more serious staff than this,so most likely nothing will happen.

Thanks good info,will remember this,also i'm considering switching although i don't have high hopes with the competition either.