open(FILE, "<myfile.txt");
@file = reverse <FILE>;
foreach (@file) {
   chomp;                              # --> Note: no need to chomp, it just forces you to add the \n again when you print
   next unless /\S/; # skip blank lines  --> Note: this is useless given that you print only line matching the /Passed CLEAN/ pattern
   if (/Passed CLEAN/) { #search string Passed CLEAN
      print "$_ \n"; # print ALL lines containing Passed CLEAN

   }
}

##</code><code>##

open(FILE, "<myfile.txt");
@file = reverse <FILE>;
foreach (@file) {
   print if /Passed CLEAN/;
}