Hi elenacherneva,
You might be best off with a profile script & audience. I don't think Samsung Native Browser will show up in our prebuilt dropdown list. You'll need to know what the user agent string is of the device you'd like to block. Then you need to find a unique way of identifying that string. After you know that:
1. setup a profile script with the name: browserUserAgent. Use something like this for the script:
That should just return their full user agent. You'll need to activate it.
2. Create an audience to evaluate the user agent. Under Visitor Profile select user.browserUserAgent. I'd probaly do something like "does not contain" and then enter the unique string that Samsung Native Browsers have.
Hope that helps.