sed, replace first line

Question

I got hacked by running a really outdated Drupal installation (shame on me)

It seems they injected the following in every .php file;

Answer 1

You can use sed with something like

sed '1 s/^.*$/

The 1 part only replaces the first line. Then, thanks to the s command, it replaces the whole line by .

To modify your files in-place, use the -i option of GNU sed.