News Courtesy of Wordfence.com:
Recently, Defiant’s analysts have been tracking a particularly sophisticated malware infection responsible for generating spam links and redirection, while still remaining relatively difficult for victims to detect.
Dubbed “BabaYaga” by our team, this infection is notable for containing code capable of removing its competition. BabaYaga actually has the ability to remove other malware.
While this malware isn’t brand new, it caught our attention with a wide array of features conducive to persistent infection. None of these countermeasures are groundbreaking individually, but taken as a whole they comprise a suite of functionality unusually comprehensive and effective for spam droppers.
BabaYaga’s primary function is to generate spam content to be hosted on the victim’s site. These pages are loaded with keyword-heavy and meaningless word salad, designed to attract search engine traffic based on those keywords.
The payoff for these spammers comes in the form of affiliate marketing services. When a human visitor reaches an infected page of the site after following a link from a search, embedded JavaScript executes a malicious redirect to an affiliate site. Any purchases made at the destination site generate income for the attacker, and at that point it becomes a numbers game.
Ryan’s Take 
Talk about dedication. I’ve had to deal with several cases of infected WordPress websites. The good news with spammy malware is that they generally don’t want to delete your existing content. It can be difficult to identify infected files and remove malicious code. I’ve used Eli’s Anti-Malware scanner plugin with great success to assist in removal of such code. It appears that this BabaYaga malware doesn’t play well with other malware and will remove them altogether.
As annoying and frustrating it can be, it is amazing that these spammers would go to such great lengths to prevent a website from breaking. The less detectable an issue is, the better the chance the malware can live on and continue generating spam links. As the source article describes, this particular malware is like a parasite. It wants to keep the host alive to keep feeding off of it.
The best way to keep malware off of your site is to install security measures. Firewalls on both the server and website level can offer protection to drastically reduce the chances of infection. Google webmaster tools may also alert the owner of a potential infection from time to time. It is important to keep an eye on all the pages that are indexed in Google. Anything that doesn’t belong should stick out like a sore thumb. Once discovered, the top priority should be backing up your website (in case you break something) and treating the infection.
