I have them printed out on paper under my blotter and have deleted same. Yes, I know, nothing is ever entirely deleted, but hackers can't get there unless direct access to your hard or flash drive. I've used Kaspersky for years and never gotten viruses, malware, trojans, or identity theft problems. If you have a strong firewall, you should be good.
Kaspersky just announced early this week that THEY got hacked and someone stole their user database and their backdoor keys! LOL!
This vulnerability on Android is in the OS and downloads automatically because of built-in update routines in the SWIPE keyboard which apparently is routinely checking for new keyboard designs. . . which allows someone to piggyback malware on the download. A firewall won't prevent this. The blessing here is the initial infection has to occur locally from some hacker sharing a WIFI connection spoofing a server.