The hack/hijack happened when you were using runelite the old way '
without Jagex Launcher
'.
Your claims are from the moment you had downloaded/installed Jagex Launcher and thus haven't anything to do with using runelite the old way.
Throughout The Internet there have been multiple malicious versions of runelite that caused much damage in The RuneScape Community. Including add-ons/plugins players used for an advantage.
Runelite as downloaded/installed through Jagex Launcher is a version controlled/checked by Jagex/JMods ... as long as you do not add/plugin new software, as you have to check its validity yourself, being malicious/rulebreaking or not.
Again I'll keep saying ... use '
Jagex's Original RuneScape Game Clients
' ... and your safe/free of any hassle possible.