A hacker using the name Sangkancil has claimed to have stolen the personal information of 7 million Israelis.
The attacker said he stole the data from the CITY4U website, which is used by local authorities in Israel to process payments such as property taxes, fines and utility bills. Israel’s current population is some 9.4 million.
If the claims are valid, the hack would be one of the most severe breaches of privacy in Israel’s history.
The National Cyber Directorate said it was investigating the hacker’s claims, but that the document leak was likely old information.
The attacker first claimed to have hacked Israeli municipalities on Sunday in a post on the Telegram messaging application.
Starting Monday, he released images of documents he said backed up his claims, including Israeli identity cards, driver’s licenses and tax bills. The documents were sent out on Telegram and online hacking forums.
The attacker offered the data for sale without disclosing the asking price, and hinted he may reveal more information in the coming days.
“This is my first surprise for the Jewish new year. Enjoy!” the attacker wrote, referring to this week’s Rosh Hashanah holiday.
Sang Kancil is the name of a series of fables popular in Indonesia and Malaysia.
The alleged attack appears similar to a hack of Israel’s Shirbit insurance company last year and comes amid a global uptick in ransomware attacks.
In the Shirbit attack, a hacking group calling itself Black Shadow broke into the insurance firm, stealing client details and demanding a ransom or it would publish the data to the internet. The company refused to pay and the hackers later said they had sold the information on the dark web.