Israel was cyber-attacked Monday.
A hacker claiming to be from Saudi Arabia brought down several high-profile websites.
They included the sites of the Tel Aviv stock exchange, Israel's national airline El Al and three Israeli banks.
The immediate damage was limited. Stock trading was not affected. And neither was air travel.
In essence, the incident adds up to politically-inspired acts of digital vandalism. "These are not particularly sophisticated attacks," said Benji Portnoy, an information security specialist with the company Symantec.
"They're actually the kind of attacks that can be done pretty easily. No actual damage to the websites that were hacked."
Even so, Israeli IT experts said on Monday there is reason to worry.
In the past couple of weeks, Israel has been the target in a series of highly publicized cyber attacks carried out by people claiming to be pro-Palestinian activists. At least one — an apparent Saudi hacker going by the name of OxOmar — published credit card information for thousands of Israelis online.
Monday morning, OxOmar reportedly tipped off Israeli news organizations that he was part of an anti-Israel hacker network that was planning to bring down the websites of Israel's stock exchange and national airline.
Yaakov Lappin, who writes about cyber crime for the Jerusalem Post, said it's impossible to verify the identity of OxOmar. But the hacker — and others like him — does seem to be having some success.
"We've seen examples of these kinds of networks rising up before in this loosely defined "Anonymous" hacking network," Lappin said. "So nothing that's taking place now is new. The only development here that's new is that it's being directed in a semi-organized way against Israel."
Lappin said Israel's government agencies are rather advanced in the ways of cyber security. But the private sector, he said, has some catching up to do. In the meantime, Lappin believes it's likely this hacker war will continue to escalate. He said he's been in touch with a number of Israeli hackers, who are planning retaliation.
"They say that they plan on publishing credit cards that were hacked from Saudi websites, Saudi shopping websites and release information about how to break into bank accounts," Lappin said. "And they're going to do a tit-for-tat campaign. Every time that Israel's attacked, they say they're going tor respond in kind."
For its part, the Islamist group Hamas which controls the Gaza strip and refuses to recognize Israel has welcomed the recent spate of cyber attacks against the Jewish state. Hamas is calling on Arab youth to join the online campaign against Israel.