hаcked by URL injection method

[Loganjiith]

My client website was recently attacked by malware (the method of URL injection hаcking). We removed all the malware urls from the site and gave the reconsideration request to google from webmaster tool. Even though Google accepted our request all my keywords went to not in 100 and other back position. How can I recover my keywords ranking?

[TomClarke]

This means a hаcker has created new pages on your website, often containing spammy words or links. Sometimes this new pages containcode that does things you didn't  intend, such as redirecting your users to other sites or making your webserver participate in a denial-of-service attack against other sites.