Following a 2016 hack attack on the US Democratic Party's servers, they rapidly multiplied after Trump's election.
Moscow: From Donald Trump's election to Brexit and the Catalan crisis, accusations that the Kremlin is meddling in Western domestic affairs have heightened fears over Russian hackers, trolls and state-controlled media.
While the first accusations against Moscow came following a 2016 hack attack on the US Democratic Party's servers, they rapidly multiplied after Trump's election, revealing a whole range of tools used by the Kremlin to serve its interests.
Fears initially centred on mysterious Russian hackers who supposedly worked for Moscow's security services as part of a cyber war but then shifted to a flood of online articles and social media posts aiming to explain Moscow's position and play up the failings of Western democracies.
In the latest episode of the saga that is dominating Trump's presidency, Russian state television channel RT, accused of broadcasting Kremlin propaganda abroad, complied with Washington demands in November to register as a "foreign agent" in the US.
A few weeks earlier, social media giant Twitter announced it would stop distributing content sponsored by RT and linked news agency Sputnik while Facebook and Google promised to do more to fight Moscow's "disinformation".
Panic has spread across the Western world: Madrid is worried about Russian-controlled "manipulation" of the Catalan crisis, while British analysts see signs of Russian influence in the Brexit vote and concerns are growing in Germany and France over possible interference in various polls.
The Kremlin, meanwhile, has dismissed the accusations as "hysterical" and "Russophobic," insisting there is no hard evidence for any of the charges.
Russia has worked hard to increase its "soft power" following what it perceived as a defeat in the "media war" during its brief war with pro-Western Georgia in 2008.
These efforts led to the expansion of Kremlin-controlled media for a foreign audience.
State broadcaster RT, formerly Russia Today, and news agency Sputnik were assigned a mission to represent Moscow's position abroad, especially on topics where Russia and the West clash such as the conflicts in Ukraine and Syria.
"Russia spends a lot of money on this (information war) and we constantly see more players," said Russian investigative journalist Andrei Soldatov, editor of Agentura.ru, a website specialising in security issues.
In 2014, Russian media reported on a new, powerful Kremlin tool: a "troll factory" in Saint Petersburg. Officially called the "Internet Research Agency," it was reportedly linked to Russian security services and ran thousands of fake accounts on social media in an attempt to influence public opinion.
According to sources interviewed by the RBK daily newspaper, it was first deployed to influence domestic politics.
The trolls, the paper said, were then reorientated from 2015 to sow unrest in the US. Here they pretended sometimes to belong to one camp and sometimes to another, spreading false information and even organising protests.
But Mark Galeotti, a security expert and researcher at the Institute of International Relations in Prague, wrote in Tablet magazine in June that the Kremlin's operation in 2016 "was about weakening Washington, not deciding who would sit in the White House" and aimed to "undermine the legitimacy of the American government, its capacity to act".
Despite these efforts, Moscow's ability to influence Western public opinion remains limited.
American officials have said that content coming from Russia and the amounts spent on it were only a small portion of the total information flow and spending.
The Kremlin nevertheless hugely increased the budget allocated to its cyber campaign during the 2016 presidential election.
Russia spent USD 50,000 on Facebook ads during the US election campaign compared to the whopping USD 81 million that Trump and Hillary Clinton spent on their campaigns.
Russian hackers, the Kremlin's shadiest instruments, have been accused of targeting the US Democratic Party, the US National Security Agency, the party of France's Emmanuel Macron and the World Anti-Doping Agency.
But Soldatov says American cyber security resources and their hacking skills are still "far superior" explaining that Russian hackers rely on methods that require few resources, such as phishing for passwords.
"The Kremlin has not gained so much from these operations, they are mainly just noise," said Soldatov.
But he still sees a danger that other countries will now want to do the same.