Tit-for-tat cyber attacks between Israeli and Arab hackers escalated yesterday, as a shadowy Israeli group released the details of 4,800 Arab credit-card holders and tried to launch attacks on the websites of the UAE Central Bank and the Arab Bank Palestine.
Early yesterday, hackers who said they were Israeli posted the credit card numbers, security codes and expiration dates of the cards, which they said they obtained from the website of a major Saudi bank.
"My name is Omer Cohen from Israel," a post together with the release announced. "I want you come to me house with all your friends and your country."
Hours later, an email sent to The National from a group calling itself IDF-Team said the group intended to shut down the websites of the UAE Central Bank and of the Arab Bank Palestine at noon.
The Central Bank said the website did become inaccessible for about 20 minutes but the problem had been quickly fixed.
The Arab Bank website remained inaccessible for most of the day when accessed in Abu Dhabi.
"They did target the website, but they didn't do any damage," said Bob Thomson, chief manager of information technology projects at the Central Bank, who described the incident as "a concentrated attack".
He said the site was up and running shortly after noon, when Etisalat blocked the hackers' access.
"Denial of service attacks are a fact of life, unfortunately," Mr Thomson said.
The hackers' email message to The National linked to an online warning calling on "terrorists to stop their terrorist acts against Israel and attempts to disrupt the normal course of life in Israel".
The name of the hackers' group, IDF-Team, mimics the acronym for Israel's defence forces, the IDF.
Yesterday's attacks came a day after a group identifying itself as "Gaza's hacking team" succeeded in breaking into the internet site of Israel's Anti-Drug Authority and planted images of armed Palestinian militants and threats including "Death to Israel".
It has not been possible to verify the identity or location of the hacking groups.
This week, hackers broke into the websites of the Tel Aviv Stock Exchange, the Israeli flagship El Al Airlines and at least three banks in attacks some officials said were aimed at hurting the country's economy and security.
The incidents drew national outrage especially because they came days after hackers proclaiming Palestinian sympathies posted on the internet the details of thousands of Israeli credit-card holders and other personal details.
On Wednesday, officials in the UAE had denied that disruptions to the websites of the Abu Dhabi and Saudi stock exchanges this week were linked to attacks planned by the same Israeli hacker group. Other proposed targets, including banks and government agencies, also denied being hacked.
This month a hacker in Saudi Arabia, named OxOmar, posted online thousands of active credit card numbers belonging to Israelis. In response, Israeli hackers posted the personal information, including email and Facebook passwords, of thousands of Saudi residents.
A cyber security expert from Good Harbor Consulting in Abu Dhabi said these kinds of attacks are common, yet can be "extremely destabilising for their targets".
"As the world increasingly takes notice of the UAE as a global marketplace and a player in international affairs, the threat from spoilers and politically driven hackers will naturally increase," the expert said, speaking on condition fo anonymity.
Israeli and Arab hackers are threatening to take further action and appear to be mainly posting their threats on a website called Pastebin, which allows users to store large amounts of data online.
The Israeli hackers who said they had disrupted the UAE Central Bank said in a statement on Pastebin that they plan to bring down the websites of Arab stock exchanges and governments, specifically naming the UAE as a target.
In interviews with the Israeli media, the Israeli hackers have outlined their motivation.
"You can call this a Zionist revenge," the mass-selling newspaper Yedioth Ahronoth on Wednesday quoted the hackers, who spoke on condition their real names not be used, as saying.
Referring to Israel's flourishing high-tech industry, they added: "They declared war on us first, but we are more talented. Israel's top export industry is full of hackers."
The paper also quoted a hacker who calls himself "Hannibal" as threatening to publicise 100,000 email details of citizens of Arab countries on Saturday and thousands more next week.
"That is how everyone will understand how dangerous and lethal the Jewish brain could be," he told the paper.