that code is bad dont use it. they are trying to scamm you again Math.random() is not secure.
Why?
Should I make another address and send IOTA there?
it's not random enough.. google it.
and yes move your iota to new address.; and be sure to create a REAL RANDOM seed first
cat /dev/urandom |tr -dc A-Z9|head -c${1:-81} in a linux terminal is secure enough?