I bet you've got ls set to colorize file names, right? What you're seeing as"control characters around file names" is VT-100 escape codes to colorize the text different ways. If you do command-line editing in Bash (vi or emacs mode) you'll also see all the control characters that implement the editing. Again, more VT-100 escape code to position the cursor, overwrite characters, etc etc.

Either you set ls to not colorize filenames, or you edit the 'typescript' file. One of the values of script is that it doesn't do any interpretation of the characters it records.