Import post from SQL file

My blog files were hacked. Somehow the hacker managed to insert a malicious code in probably all my WordPress php files.

Since then, it’s impossible to access the admin section.

I changed the subdomain folder name, so the usual URL was not accessible to general public anymore.

The database of the old blog seems to be fine. I have backed it up to a .sql file, using tools offered by my host service.

Now I have a brand new version of WordPress installed in a different subdomain and I want to recover the old posts from the SQL file. How can I do that?