One of Israel's largest cyber-security companies, Check Point, was taken down by a group of hackers calling themselves "Anonymous Sudan" on Tuesday afternoon.
However, after a short while, the website seemed to return to operating as normal.
Earlier in the day, the websites of multiple major universities in Israel were also attacked by the same group, and were down for several hours.
Among the websites unavailable for browsing were the sites of Tel Aviv University, the Hebrew University of Jerusalem, Ben-Gurion University of the Negev, Haifa University, Weizmann Institute of Science, Open University of Israel and Reichman University.
Statement from the Check Point spokesperson
"All our sites are functioning well despite a large-scale attack on them," Check Point's spokesperson said in a statement. "The company's website is protected against DDoS (Distributed Denial of Service) attacks at the highest level. [It is] one of the strongest websites in the world.
"The hackers used a huge amount of requests [in order to] affect - for a few minutes- the ability to reach the site. Thanks to [our] protections, the site works as usual and was not damaged by the attack."
The hacker group's statement
The group published a statement on its Telegram account, listing the sites it attacked. "Infrastructure: Universities - Israel education sector has been dropped Because [sic] of what they did in Palestine," the statement read.
The group also added that this wasn't its main attack, which will occur on April 7. It is not clear if the attack also penetrated into the institutions' systems.
This attack is part of a campaign called OPIsrael, in which activists try to attack targets on the Israeli internet, according to Ynet News. Some of the sites attacked on Tuesday are already available again.
"These are service-preventing attacks - those that only bring down websites and do not steal information and that can be recovered from relatively easily. However, it can be assumed that these groups are trying to produce more significant attacks, including ransom attacks and data theft," cyber security firm Check Point told Maariv.
According to Check Point, the Anonymous group also shortly attacked websites related to several medical centers, including Rambam Hospital in Haifa. However, the hospital denied the attack.