use strict;
use warnings;
use Data::Dumper;

my $s = <<'ENDSTR';
aaa       : AAA
bbb       : BBB
ccc       : CCC
ENDSTR


my %hash = map { split( /\s+:\s+/, $_, 2) } split ( /\n/, $s );
print Dumper \%hash;

__END__
$VAR1 = {
          'bbb' => 'BBB',
          'ccc' => 'CCC',
          'aaa' => 'AAA'
        };