Less than two weeks after 30,000 computers at a Saudi oil company fell prey to a virus, a Qatari gas firm's Web site and corporate network are also down because of a virus. The virus did not however have impact on production operations and cargo deliveries.
Some reports stated that a hacker group calling itself Cutting Sword of Justice issued a public statement the day Saudi Aramco was attacked, claiming it had sent a virus to destroy 30,000 computers to protest the Al-Saud regime's support for government repression in neighboring countries. A subsequent public message from hackers indicated that the Shamoon virus was used in the attack.
ref: cnet