The website of the news agency Reuters has been hacked by the Syrian Electronic Army (SEA) again - condemning the news site for publishing "false" articles about Syria.
People on Twitter raised concern after articles from the site seemed to redirect to a message from the SEA, known computer hackers who support the government of Syrian president Bashar al-Assad.
It is the first public, virtual army in the Arab world to openly launch cyber attacks on its opponents.
The SEA message stated: "Stop publishing fake reports and false articles about Syria!
"UK government is supporting the terrorists in Syria to destroy it. Stop spreading its propaganda."
But it appears the security breach is not the fault of Reuters, but web advertising site Taboola, which now puts at risk other major news outlets, analysts say.
The SEA reportedly corrupted Taboola web ads on Reuters articles to redirect traffic to a page under the hackers' control.
One commentator believes any client of Taboola - including the world's biggest news sites such as Yahoo!, the BBC and Fox News - could be at risk "anytime now".
The SEA message was up on the news site at around 12noon but has since been taken down.
No explanation has been published by Reuters.
But Taboola's CEO and Founder Adam Singolda released a statement on Sunday, saying the attack happened through a 'phishing mechanism', which was rectified within half an hour of the security breach.
He wrote on the company's blog: "Today, between 7am - 8am EDT, an organization called the "Syrian Electronic Army" hacked Taboola's widget on Reuters.com.
"The intruder was redirecting users that accessed article pages on reuters.com to a different landing page.
"The breach was detected at approximately 7:25am, and fully-removed at 8am. There is no further suspicious activity across our network since, and the total duration of the event was 60 minutes.
"While we use 2-step authentication, our initial investigation shows the attack was enabled through a phishing mechanism. We immediately changed all access passwords, and will continue to investigate this over the next 24 hours."
The last time Reuters was hacked by the SEA was when hackers posted a false article in 2012 claiming that Saudi Arabia's foreign minister Saud al-Faisal was dead.
Many people took to Twitter to complain about the alleged hacking.