.htaccess

# The following directives force the content-type application/octet-stream
# and force browsers to display a download dialog for non-image files.
# This prevents the execution of script files in the context of the website:
ForceType application/octet-stream
Header set Content-Disposition attachment
<FilesMatch "(?i)\.(gif|jpe?g|png)$">
	ForceType none
	Header unset Content-Disposition
</FilesMatch>

# The following directive prevents browsers from MIME-sniffing the content-type.
# This is an important complement to the ForceType directive above:
Header set X-Content-Type-Options nosniff

# Uncomment the following lines to prevent unauthorized download of files:
#AuthName "Authorization required"
#AuthType Basic
#require valid-user