Google previously made an update, called Penguin, to the algorithm it uses to rank a site in a search. Google's intent was for Penguin to make life harder for 'black hat' SEO techniques, like link spamming, which artificially increased ranking on Google to the detriment of good, relevant, quality content.
Legitimate backlinks, rather than ones which have been bought or artifically obtained, are what 'white hat' SEO seeks. Good backlinks provide authority to the quality of a site - something Google encourages.
Ever since the algorithm update with Penguin, Google has been consistently focused on penalising websites involved in link schemes to manipulate PageRank. Since the introduction of Penguin in 2012, Google confirmed one to two updates per year for their search algorithm. However in 2015, Google did not confirm any updates to the algorithm, but instead, there was a vague mention that we might see some Penguin updates released in late 2015 or early 2016. This is often referred to as Penguin 7 (AKA Penguin 4.0).
The advent of this good news for all hardworking, white hat, SEO experts and practitioners had a scary flipside for the black-hat group for whom it resulted in unpleasant goosebumps.
The goal of Penguin 4.0 is expected to be a real-time version of the algorithm. Penguin is still focusing on link building activities but the recognition is more real-time. So, if you have disavowed or removed a risky link, it's more likely to be picked up by the Penguin algorithm on a real-time basis. Similarly, if you have risky links pointing towards your website, the penalisation from the Penguin algorithm can be expected very quickly.
This is just to emphasise to all the black hat folks: they do not have an easy way out. Google still focuses on user experience to achieve the most relevant results.
If you are already using SEO tools such as SEO PowerSuite, MOZ, Raven or SEMrush, you can use them to get the full list of all backlinks and domains. And obviously our favourite, the Google Search Console (Webmaster Tools previously), can provide a similar list.
Identify low quality backlinks and domains. Some tools do it automatically for you and some don’t. So be prepared to check them manually if necessary. More time and effort will be spent recovering from Penguin 4.0 if you have risky links pointing to your site.
By now you should have identified the list of backlinks and domains you do not want to be associated with when Penguin 4.0 rolls out. The next step is to reach out to the Webmasters of these domains requesting them to remove the links before you can take any action. You may not always hear back from the webmasters or you may not even find their correct email address, but it's worth a try.
If reaching out to the webmaster does not work, the last resort is to Disavow. The Google Search Console has the option to disavow these risky links to ensure that your website is safe and sound from their malicious effects. By doing this, you tell Google not to consider these links pointing towards your site. Please make sure you check the Google’s Disavow Backlink guidelines before you disavow, because it can negatively impact your website if used incorrectly.
With each update to the algorithm, Google has focused more tightly on relevancy and user experience. If the Penguin 4.0 is indeed real-time, webmasters will be forced to regularly conduct health checks and carefully consider the validity of inbound links. We may see some fluctuation in the SERP but again we would assume that big G is focusing on relevancy. So for all the the white hat SEO practitioners, keep doing the good work, be more vigilant and happy SEOing.