Yes, the phone was purchased brand new from Sprint. I've had it since the HTC One first came out. No updates were installed directly prior. At least not that I know of. The last time I updated was about 2 weeks ago. No apps were installed/uninstalled prior.
However forgot to plug in last night and the battery died. Came on this morning only b/c my alarm was set (noticed that it came on in airplane mode) and then it turned right back off. plugged it to charger immediately.
I noticed it was frozen about 5 hours later.
The last thing I did was either make a call or check my FB.