Facebook accused what it said was the cyber wing of the Palestinian Preventive Security Service (PSS), which is loyal to President Mahmoud Abbas, of running rudimentary hacking operations that targeted Palestinian reporters, activists, and dissidents, as well as other groups in Syria and elsewhere in the Middle East.
Mike Dvilyanski, Facebook's head of cyber espionage investigations, told Reuters that the PSS had intensified its activities over the past six months or so.
He said Facebook believed that the organization had deployed some 300 fake or compromised accounts to target roughly 800 people overall.
None of the targets were identified by name.
Facebook said it had issued individual warnings to the users concerned via its platform and removed the rogue accounts.
Attributing malicious activity online is notoriously tricky, but Dvilyanski said the world's largest social network "had multiple data points that linked this cluster of activity to the PSS and our confidence in this attribution is quite high."
According to the Facebook report, the techniques used by the PSS focused heavily on tricking users into downloading off-the-shelf spy software, for example by creating dummy Facebook accounts with pictures of attractive young women.
Facebook said the hackers also posed as journalists and, in some cases, tried to get targets to download spyware masquerading as secure chat apps or an app to submit human rights-related stories for publication.
Some of their Facebook pages posted memes, for example criticizing Russian foreign policy in the Middle East, to lure particular followers.
Facebook also said it had taken action against another long-running campaign linked to a different hacking group, often dubbed 'Arid Viper.' It did not say who was behind the group.
Facebook said Arid Viper had operated fake Facebook and Instagram accounts and more than a hundred malicious websites, as well as expanding into iOS surveillanceware.
The targets included Palestinian government officials and security forces, it said.
In this context, the Palestinian Independent Commission for Human Rights (ICHR) has called on the cabinet and the public prosecutor to hold a transparent investigation on the report published by Facebook.
ICHR classified the matter as “highly serious”, urging the government to take prompt procedures to protect the privacy of citizens.