You need to remove the malware code that was inserted and restore the backup. You do have a backup right?
Thanks for your reply. I am not sure about the backup I will contact my webdesign team to see what they can do. Do you have anymore tips? Thank you all!
If you do not have backups, contact your host, it may happen they have. But they aren't obliged to store backups for you.
It is very likely your website was hacked due your forgetting to update it. The version of WordPress you are running now may allow hackers to compromise your site. So once you have someone remove all of the malware, or recover your site from backup, you'll need to run (not walk) to ensure all of your scripts are updated (wordpress, plugins, etc.).
Yeah HackRepair is right, you always must update to the latest of Wordpress if thats the CMS that your using, make sure all your plugins are updated and everything because outdated versions of Wordpress get hacked pretty much automatically by auto bots looking for vulnerable websites to hack. When Google notices your website was hacked and has malware on it, it will really effect your search engine positions.