Nothing on the Internet is safe anymore. You don't want others finding things out about you then don't store anything on a physical disk. Use USB Flash drives then unplug them when not in use. It doesn't matter whether you have 128, 256 or 512 bit encryption you're still vulnerable to attacks
I myself I do not even store usernames and passwords. Every time I log in somewhere I have to type in manually each and every time. My cleaning utilities run every 3 minutes to keep Cookies, Temp Files and all the clutter cleared out. Install a Sandbox then if your computer or device does happen to run into any trouble just close the Sandbox and the problem is gone.
Now that the Russians are heavily sanctioned they'll pull all kinds of tactics just to get their hands on your hard earned dollars.