A series of corruption allegations were made on the official accounts of FIFA President Sepp Blatter and the World Cup, some linked to 2022 World Cup host Qatar, including one libelous post about the Emir of Qatar.
"It was decided that the president Sepp Blatter is to step down due to corruption charges," the hackers posted using the (at)FifaWorldCup account.
With FIFA unable to regain control of either account, which have more than 500,000 followers combined, the media department confirmed by email that they had been hacked.
"We are looking at this issue at the moment," FIFA said in a statement. "In the meantime, to avoid any doubt, we kindly ask you to verify and check any statements that you see on a FIFA twitter account with the FIFA Media department."
The Syrian Electronic Army — hackers sympathetic to Syrian President Bashar Assad — posted messages claiming it had posted the tweets. The group also recently claimed to have hacked the Twitter accounts of the BBC Arabic service and broadcaster Al-Jazeera.
One message Monday also taunted Twitter, which has shut down other SEA accounts.
"Twitter (hashtag)Failure... You can't stop us!" read one of 14 rogue posts on the official World Cup account.
The hackers also reminded FIFA that the Syria national team was kicked out of the 2014 World Cup qualifying tournament in 2011 for fielding an ineligible player.
"The decision to disqualify the Syrian team on a technicality was found to be politically based," one message read.