The extremists are distributing warped propaganda containing pledges to attack fans and players with guns, knives and vehicles.
Argentina’s Messi and Portugal’s Ronaldo have become the latest targets in an image circulated by ISIS.
The players are pictured being pinned to the ground with their heads being hacked off in a packed football stadium by masked jihadi fighters.
Captioned “Your blood will fill the ground”, the poster shows two terrorists in balaclavas and grey jumpsuits crouched over Messi and Ronaldo.
Other propaganda posters show ISIS threatening “we will be there” in front of a picture of the World Cup logo.
instructions have been revealed encouraging wannabe jihadis to strike using trucks and cars
Guns, knives and bombs are also urged to be used by ISIS fighters.
And the poster even includes a guide to the “deadly points in the human body” for “targeting the infidels in or out of stadiums”.
Posters include ISIS urging terrorists “kill them all” and promising to make it an “explosive cup”.
ISIS often produces propaganda in run-up to major events in means to incite violence and scare people.
The latest shocking threats were revealed by cyber intelligence firm Sixgill which monitors ISIS chatter and probes the so-called Dark Web.
Sixgill revealed chat had intensified up over the past week with a series of direct threats to the World Cup.
The tournament kicks off on June 14 and Russian authorities have been working non-stop smashing terrorist rings ahead of the global showpiece.
Back in March, Russia busted an ISIS “sleeper cell” while in April secret services found ISIS fighters armed with AK-47s and bombs.
The FSB has identified terrorism as the biggest threat to the World Cup but insists security has been stepped up thwart any potential attacks.
Chris Hawkins, a senior analyst at Jane’s Terrorism and Insurgency Centre, said: “There are numerous terrorism threats affecting the World Cup.
The main one, as with the rest of Russia, comes from lone operators with low capabilities.
Tactics will likely include knives and vehicle attacks targeting fans visiting games or the surrounding areas.
Mr Hawkins said: “Aspirational targets will include match days, particularly in Moscow and St Petersburg – the two cities that will have the largest concentration of foreign visitors, with Moscow hosting the key fixtures of the World Cup, including the final and the opening fixture.
“Sochi and Volgograd are two other cities at heightened risk due to their proximity to the North Caucasus region meaning they are logistically viable cities for militants to stage attacks.”
The terror expert added that returning ISIS fighters pose as a serious threat due due to weapons and bomb-making experience.
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He said: “These fighters have had combat experience and have had training in operating military-grade firearms as well as manufacturing IEDS.”