字符串中的字母之间的空字符

i have a problem using some php functions on a string i get from a file. When i read it in notepad++ it seems to have no spaces but when i echo in cmd there appear to be spaces between the letters, and if i capture that output in a file and read it with notepad++ those characters are red as a black NULL. How is that character expressed so i remove it. I am including a file since i cant write what happens here. thank you in advance

PS the string was written in a file with vbscript btw

Use str_replace:

$str = file_get_contents("out.txt"); 
$str = str_replace("\0", "", $str); 
file_put_contents("out1.txt", $str);