Welp, since all the transactions are consisting of virtual data from electronic device (computer).
Attackers are everywhere. be it scammers or hackers. Im not pretty sure if there is say "near" perfect virtual/online security.. since the "internet" is by what it serve as purpose... network sharing by users...
just to add
If the world depended on cryptocurrency.. there will be many loses if an EMP attack (which disables all electronic devices..) breaks out and take down most networks