The database from Machon Mor released later on Tuesday includes information on the medical treatment, appointments, test results, and vaccinations of about 290,000 patients of the medical centre, according to The Times of Israel.
Head of the Israel Internet Association Yoram Hacohen described the recent attacks to the newspaper as "one of the most serious attacks on privacy that Israel has ever seen", adding that "Israeli citizens are experiencing cyber terrorism… This is terrorism in every sense and the focus now must be on minimising the damage and suppressing the distribution of the information as much as possible".
Hacohen told The Times of Israel that Telegram was partially responsible for the leak of the data for not limiting the spread of private information, stressing the importance of legal and technological action by Israel to remove damaging information online.
Earlier on Tuesday, Black Shadow uploaded to a Telegram channel the database of user information from the Atraf LGBTQ dating website, including users' names, locations, and even HIV status, after the service refused to pay a ransom of $1 million in digital currency to prevent the leak of information.
On Friday, the Black Shadow group hacked the Israeli internet hosting company, CyberServe, taking down its servers and a number of sites, including the Atraf LGBTQ dating website, as well as the websites of tourism company Pegasus, public transportation company Dan, and children's museum Kavim.
These cyberattacks by Iran-linked hackers come a week after an unclaimed cyberattack crippled Iran's gas distribution system on 26 October, which Iran has blamed on Israel and the United States.