Two or three hackers are responsible for releasing the credit card information of hundreds of thousands of Israelis on Monday, an internet security firm said on Tuesday. According to Maglan Internet Defense Technologies, the hackers are probably citizens of Kuwait, Saudi Arabia and Croatia. Among those whose credit card details were revealed is Labor leader Shelly Yachimovich.

According to Shai Blitzblau, Managing Director of Maglan, the group is also responsible for hacking other websites around the world, including Islamic ones. For this reason, said Blitzblau, the claim that the hackers targeted Israel’s economy is probably unfounded.

One hacker, who claimed to be a member of the Saudi hacking group, Group-XP, said on Monday that he revealed information including credit card details, personal addresses, names, phone numbers and ID numbers of individuals listed on the website, One.co.il.

Israeli credit card companies said Monday that the list is repetitive and only includes 14,000 Israelis. They said they have blocked all the cards on the list, and will return customers their money should any purchases be made on the cards.

The websites that were hit include sale365.co.il and bizmakebiz.co.il. Representatives of the latter said however that the website does not keep its costumers’ credit card details and that the only details obtained by the hackers were names of businesses and users.

Another website targeted was ezpay.co.il, which claims to use a more secure standard called PCI DSS. The hackers also hit a database of a website which sells Jewish gifts to the U.S. and a business network of Jewish American youth.

Joey Pekeg, CEO at Israeli Cyber Defense Institute, said these attacks can be prevented by using more secure standards such as PCI DSS. The standard “shows a company that does business on the Internet exactly what to do, step by step,” he said. Yet he added that few businesses in Israel use this standard.