Image copyright Reuters Image caption Ziv Orenstein of human rights group B’Tselem
Security agents are believed to have used spyware to hack phones of 15 staff members and activists at a human rights organisation, including members of parliament, rights groups say.
The researchers say the malware was sent via WhatsApp and detected only after it had been running for more than 48 hours.
Israeli police have yet to comment on the claims.
Reports of Israeli intelligence agencies hacking foreign activists had previously been confirmed.
Ms Naser, an Israeli journalist, reported that Israel’s Shin Bet agency had given her a copy of the malware, which she said was for the computers of NGO staff members at a Gaza-based organisation called Muhammad Jamal Foundation, which works with children at risk.
Dr Omar al-Ghoul, the president of the organisation, said his staff had believed that the downloads were linked to the work of the election commission in Gaza.
“It was a great shock to all of us,” he told the Al-Monitor news website.
Organisers at the International Committee of the Red Cross expressed concern that the attack could affect their efforts to negotiate with different parts of the Israeli prison system.
Amnesty International and B’Tselem were also named as victims of the malware.
Israeli journalist Ms Naser said she was first made aware of the discovery after receiving a subpoena from two banks that had been targeted.
Image copyright Getty Images Image caption The MetaScrypt software reportedly went undetected for more than 48 hours
She also received an email from The Citizens Brigade – an anti-government watchdog group – containing screenshots of the Pegasus malware – named MetaScrypt – and details of who had activated it and its location, she wrote in the Times of Israel newspaper.
The sharing of the software allowed it to spread and was a sign of collusion between the powerful and the powerless, she wrote.
She said she had not leaked the files as she did not wish to harm others, as she did not yet have access to them.
Ori Nir of the Citizens Brigade also denied she had handed over the files, saying they were stolen from the phone of one of its staff members.
The malware was believed to have been tested on WhatsApp by Hadar Susskind, a former research fellow at Harvard’s Kennedy School of Government who recently set up his own information security firm.
The Citizen Brigade has posted screenshots on Twitter and sent reports to the security experts at BCI, indicating that they had found the software on 15 phones.
The Citizen Brigade group says that without that person’s help, they would have been unable to share the files widely.
Meanwhile, Israeli spies may have also hacked phones belonging to MK Haneen Zoabi, who is representing a Palestinian motion against the country at the United Nations, Human Rights Watch has said.
Mikko Lehtonen, a spokesman for the European Parliament, said the organisation was aware of the allegations.
“All European Parliament members are given the necessary security information to protect themselves against such risks.”
In an online statement, the alliance of civil society groups Code Pink also said it had examined the group’s arsenal and the group’s phones had reportedly been tapped.
A spokesman for Israel’s foreign ministry declined to comment on the allegations.