More than 400 credit card numbers claimed to belong to Saudi Arabian citizens were released this week in apparent retaliation for the release of 15,000 active credit card numbers of Israelis last week.
The data was posted publicly on Pastebin by someone claiming to be an Israeli called Omer Cohen, or "0xOmer" on Twitter. The data includes credit card numbers and expiration dates. Some entries contain the cardholder's name.
0xOmer also wrote on Twitter that the CVCs, or the three digit code on the back of the card, would not be released. The code is usually needed to conduct a transaction with an e-commerce vendor over the internet.
One of the victims said the credit card number released with his email address was accurate. The victim, who lives in Saudi Arabia, said he had not had time to cancel the card yet.
On Saturday, Israel's Deputy Foreign Minister Danny Ayalon equated cyber attacks with terrorism, saying the country is prepared to respond. The comments followed the release last weeks of tens of thousands of credit card numbers of Israeli citizens by a hacker going by the name "oxOmar".
However, Israel's Banking Supervision Department said last week that only 15,000 of the numbers were active.
On Monday, Ayalon's personal website was targeted by hackers. His website briefly redirected to a different domain containing Arabic messages and the note "Hacked by Foxy + TKL and Gaza HaCKeR Team".
Although efforts to contact Ayalon's office were unsuccessful, he wrote on his Facebook page on Monday that "this morning some Muslim extremists hacked into my website to try and prevent me from continuing to do my work on behalf of the State of Israel, especially my online public diplomacy. We will not be weakened nor silenced by such attempts!"