Can anyone explain what happened on my TV?

[AZJonnie]

8. So probably don't fire up the webOS browser on your TV and log into your bank account from it

or other financial institutions. That's pretty much good advice on any connected internet device that doesn't get frequent updates like Windows, Android, and MacOS.

If you're worried about it though, a cool thing about all such devices like TV is their OS's are trivial to completely reset from the factory firmware (which is not hackable). Takes some time to set all the settings again, but it's not that big a deal in most cases, unless you like paid to have it professionally calibrated.

Can do the same with the Sling device.

My advice is that if it starts crashing regularly, do a factory reset. Then let it immediately download and install updates, before you do anything else, so it gets the most up-to-date protection. Then exercise a modicum of caution, esp. re: installing anything from a vendor you don't trust. Stick to mainstream, well-known apps if you're going to install anything. Since you have a SlingTV you probably don't really have to anyway.