while(<DATA>) {
    chomp;
    my ( @bits, $rest );
    ( $bits[0], $rest ) = split ':', $_, 2;
    $bits[0] =~ tr/()//d;
    push @bits, ($rest =~ m!\(([^)]+)!g) if $rest;
    print "@bits\n";
}

__DATA__
OFF
SUCCESS: (abc)
ERROR(1): disk number (27) crashed at (11:03)
WARNING(1): system is rebooting