Government sites aren't the only ones targeted. Many other apparently randomly chosen Israeli sites have been hit, including an Israeli massage parlor, an obscure luxury car site, an accountancy practice and a university website.
Erel Margalit, chairman of Jerusalem Venture Partners, a leading Israeli venture capital firm, has invested significantly in Israel's cybersecurity system but said more must be done.
"Israel has the Iron Dome system (to intercept incoming rockets), but it needs a cyberdome," he said, noting the government just approved collaboration on the first-ever private cybersecurity incubator to further invest in the industry.
"The start-up nation is also a cybernation, it needs to be defended, and Israel is known to be quite advanced in this field," he said. Israel is often called the start-up nation because of its technology companies.
Kenig said his company had seen evidence the attackers were ramping up their efforts.
Technolytics Institute, a private U.S. consultancy, said Israel is prepared to confront incoming threats, rating Israel as fourth behind Russia, China, and the U.S. for cyberintelligence capabilities — not just defensive, but offensive, as well.
Kevin Coleman, senior fellow at Technolytics, said while Israel has invested significantly in the industry, Anonymous has become a new, threatening "virtual state" of sorts.
"When you think about conflict in general, you think about borders, but the internet doesn't have borders," he said. "So how do you retaliate against a loose coalition? How do you negotiate a cease-fire with Anonymous? We're at the tip of the iceberg in figuring out how to deal with virtual states and creating a new paradigm," he said.
"We need to do it quickly, though. This is the warfare of the future."
Satter reported from London.