Spyware made by an Israeli firm blacklisted by the US has been used to target critics of Saudi Arabia and the readers of a Middle Eastern news website, a report has revealed.

Iran PressMiddle East: Researchers at web security firm ESET say they have found links between attacks on websites in the Middle East and the UK, and Israeli spyware firm Candiru.

In the attacks, known as 'watering hole attacks', malware is launched against users of websites whose readership is of interest to the malware user. The attacker can identify information about the targeted users, including browser and operating system specifics, the ESET report revealed. In some instances, the attacker can take control of the target’s computer.

The ESET researchers said that at least 20 websites were targeted by spyware, including that of London-based news website Middle East Eye (MEE). The targets of the attacks had "links to the Middle East and a strong focus on Yemen and the surrounding conflict", the report said.

MEE has condemned the attacks, with editor-in-chief David Hearst saying that the revelations come as no surprise.

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