Read all about it: The biggest fake news stories of 2016

This year has been a roller-coaster one for news, full of political upsets and shock outcomes. But while the Brexit vote and the U.S. election were making headlines, so too were apparently genuine stories that Pope Francis had endorsed Donald Trump and Hillary Clinton sold weapons to ISIS.

After being fact-checked, it quickly became apparent that these stories were almost entirely fabricated. And while a slightly closer inspection would have shown that Popes are traditionally politically independent and no evidence has been found that Hillary Clinton has financial links to the so-called Islamic State, many people took the stories at face value.

According to data from Buzzfeed published last month, these stories boasted nearly two million Facebook engagements, in the three months leading up to the U.S. election. To put that figure into perspective, during the same period, the top performing Facebook story for the New York Times racked up just over 370,000 engagements. A Buzzfeed investigation traced some of these fake publishers to a small town in Macedonia called Veles - where it discovered that over 140 fake news sites are based.

CNBC looks at some of the biggest top performing fake stories of 2016, using engagement figures from Buzzfeed.

The story was originally published by a site called WTOE 5 News before being copied by a popular fake news publisher Ending the Fed. By November 8, the story had picked up 960,000 Facebook engagements, according to Buzzfeed.

WTO5 News has since shut down its website. However, when it was operational, it openly admitted to fabricating content and even had a disclaimer on its homepage saying: "most articles on wt0e5news.com are satire or pure fantasy." Ending the Fed has taken down its version of the article, but is still publishing fake news and growing its audience on Facebook; it currently has over 350,000 followers.

During a press conference on October 2, Pope Francis spoke publicly about the U.S. election for the first time, saying "I never say a word about electoral campaigns" and that there were "difficulties" with both candidates; Reuters reported. Francis also spoke out against the dangers of fake news on December 7 in an interview with the Belgian Catholic Weekly, calling it a "sickness."

This was published by Americanmilitarynews.com in May and racked up 893,000 engagements, according to Buzzfeed's data. The article claimed that back in 1991, a bunch of Marines had been left stranded after Operation Desert Storm, and that Donald Trump had found out about it and sent his own plane to collect them.

The story can be traced back to Sean Hannity, a popular conservative political commentator. His site, Hannity.com, still has the article up and says it has been confirmed by Trump's team. The Washington Post fact-checked Hannity's article and the real story is slightly different.

A Trump-branded plane did indeed pick up the Marines, but it wasn't Donald Trump's personal jet. It was a Boeing 727 that was part of Trump Shuttle Inc, an airline owned by the president-elect from 1989-1992. TSI never turned a profit and by 1990 it had defaulted on its loans. The planes were eventually seized but, before the business was sold, TSI contracted out planes to the U.S. Army.

The "Pizzagate" conspiracy theory emerged after WikiLeaks released emails from Hillary Clinton's campaign chairman, John Podesta. Reading the emails, online communities such as 4chan and Reddit began theorizing about possible double meanings which could be inferred from the exchanges. It was quickly decided that emails about social gatherings involving "pizza," were code for something much darker; a secret underground human trafficking/child sex abuse ring, involving senior members of the Clinton campaign.

There has been no evidence to support claims that Comet, the Washington pizzeria mentioned in the emails is up to any wrongdoing. In fact, after investigating the claims, the Metropolitan Police Department of the District of Columbia characterised the matter as a "fictitious conspiracy theory". The New York Times, Fox News and the Washington Post have also failed to find any unlawful activity at the restaurant.

Nearly a million people read this story on Facebook. Actually the piece did not even mention Ireland, it references Inishturk - a small island off the coast of Ireland which has no say on Irish immigration policy. Furthermore the article, which was published by Winning Democrats, referenced how Canada has adopted an open door immigration policy for disgruntled Americans - which it hasn't. Nonetheless, the story generated 810,000 engagements.

Published on August 4, this article was written by The Political Insider after WikiLeaks founder Julian Assange made comments about Hillary Clinton during an interview in late July. The article states that Assange contended "Hillary Clinton and her State department were actively arming Islamic jihadists, which includes ISIS…" and generated some 789,000 engagements, according to Buzzfeed data.

What Assange actually said, was that a Hillary Clinton-led State Department had approved weapon shipments to Libya during the intervention in 2011, and that those weapons had later ended up in the hands of jihadists. Before Election Day, the article had 789,000 engagements according to Buzzfeed.

The article, which generated some 567,000 Facebook engagements, according to Buzzfeed, was originally published by the Denver Guardian on November 5. The site has since been deleted, but it once called itself "Denver's oldest news source". In reality, that title belongs to the Denver Post, which has been publishing since 1892.The Denver Guardian article prompted the Post to publish a piece titled "There is no such thing as the Denver Guardian, despite that Facebook post you saw." In its article, the Denver Post draws attention to the fact that the contact address listed for the Denver Guardian is actually just a vacant car park.

This was another big clicker for the website Ending the Fed with over 538,000 Facebook engagements, but a lot of the content seems to have been sourced from the right-wing news and commentary site Breitbart News. All that can really be proven is that FBI Director James Comey has worked for organizations in the past that have donated money or partnered with the Clinton Foundation.

Brietbart has so far been unable to produce proof Comey directly took part in, or benefitted from any of the transactions. As for the taxes claim: Peter Comey is employed in some capacity by DLA Piper - a multinational law firm. According to Breitbart, DLA Piper conducted an independent audit of the Clinton Foundation in 2015, although there is no evidence to support this claim.

The only clear link between DLA Piper and the Clinton Foundation is one of the firm's partners, Kathy Keneally. Before joining DLA Piper's New York office in 2014, Keneally worked as the Assistant Attorney General for the Justice Department's Tax Division. During her time at the DOJ Keneally carried out a four-year-long review of the Clinton Foundation's tax returns between 2010 and 2013.

WNDR is a self-confessed fake news outlet and the site's disclaimer points out that its content is fictional in nature and meant to be read as satire. Nonetheless, this article went viral among Trump supporters online and racked up over half a million engagements before November. WNDR alleged that a top ISIS leader released a video endorsing Hillary Clinton and threatening potential Donald Trump voters, calling them "infidels".

This is another story copied and reposted by hundreds of fake news sites, often shared with the hashtag #ISISwithher, and clocked up some 522,000 Facebook engagements according to Buzzfeed.

Within its first week, this article had already captured the attention of 481,000 readers, according to Buzzfeed. It has been published by a plethora of fake news sites, but it got the most attention on ConservativeState.com, one of the best performing Macedonian fake news outlets.

While the quote was made up, it is loosely based on a comment Hillary Clinton made in a private speech to Goldman Sachs, an excerpt of which was published by WikiLeaks. What Clinton actually said was that she would like to see more successful business people enter politics.

After tapes surfaced of Donald Trump and broadcaster Billy Bush making obscene comments about women, so did this satirical story about the President-elect fondling one of America's most famous drag queens.

Published by the satirical site World News Daily Report on October 15, the article said that RuPaul had been grabbed by the president-elect during a party in 1995. Buzzfeed data shows that before Election Day, this article had over 285,000 Facebook engagements.

Disclosure: CNBC parent NBCUniversal is a minority investor in BuzzFeed.

Follow CNBC International on Twitter and Facebook.