knoppix@Microknoppix:~$ perl -E '
> $str = q{"evt":"Login","time":"now","msg":"Login success, welcome back!"};
> %hash = 
>    map { split m{:} }
>    split m{(?<="),(?=")}, $str;
> say qq{$_ => $hash{ $_ }} for keys %hash;'
perl: warning: Setting locale failed.
"msg" => "Login success, welcome back!"
"evt" => "Login"
"time" => "now"
knoppix@Microknoppix:~$