https://miteshshah.github.io/sysadmin/terminal-escape-sequences-the-new-xss-f...
Ъ:
$ printf '#!/bin/bash\necho doing something evil!\nexit\n\033[2Aecho doing something very nice!\n' > backdoor.sh
$ chmod +x backdoor.sh
$ cat backdoor.sh
#!/bin/bash
echo doing something very nice!
$ ./backdoor.sh
doing something evil!