use strict;
use warnings;

my $out = "Backup/backup.txt";
my $logfile="log.txt";
my $MAL = '^"_.*"$';

my $logfile_new;

open LOG, "<", $logfile or die "Cannot open $logfile for read :$!";
open OUT, ">$out" or die "Cannot open $out for write :$!";

while ( <LOG> ) {
  if ( $_ =~ /$MAL/i ) {
  print OUT $_;
  }
}