We received an email from google webmaster tools last night that our website has been hacked. This is the message we received:
Unfortunately, it appears that your site has been hacked.
A hacker may have modified existing pages or added spam content to your site. You may not be able to easily see these problems if the hacker has configured your server to only show the spam content to certain visitors. To protect visitors to your site, Google’s search results may label your site’s pages as hacked. We may also show an older, clean version of your site.
It appears that only spam content has been added to the website. Which is providing bad search results and the site has been marked hacked. We recently had a marketing company that inserted a retargeting tag into the website. I'm wondering if there is a way tell where the breach of security happened? If it was the marketing companies tag or some other cause?