Saudi Arabian authorities on Wednesday denied claims that Israeli hackers had crippled the website of the oil-rich country's capital market, saying the system was operating normally.

Israeli hackers claimed they brought down the websites of both the Saudi Stock Exchange (Tadawul) and the Abu Dhabi Securities Exchange (ADX) on Tuesday, in the latest episode of a continuing cyber war between hackers in Israel and other countries.
The hackers wrote that the attack came in response to the “pathetic” hacking of Israeli sites on Monday, in which a group of hackers calling themselves the “nightmare group" caused disruption to the El Al and Tel Aviv Stock Exchange websites.
Saudis deny stock exchange website infiltrated by Israeli hackers - Haaretz Daily Newspaper | Israel News