Page Not Found This page no longer exists... requests should not count as session

Page Not Found This page no longer exists... requests should not count as session

My site and I am sure other sites are receiving a lot of malicious traffic that ends in "Page Not Found This page no longer exists". I think that if a request results in this then it should not be counted as a session and should not be in the session total count.

But a session is started and is still in place and provided the visitor isn't identified as a spider, then they have an active session that could ultimately result in a sale.

Out of 1000 Page not founds.... the chances of 1 of them even browsing the website is slim. Most of them are malicious looking for /wp-admin/login.php or /ad.txt or some such nosense..... IF the session hits a valid page then yes count those as sessions but not the PNF's.... I would rather know the truth that 5 people looked at my website for the day instead of seeing 195 and knowing that most were bots or malicious hackers.