UPDATE 1 — Investigators hunt French supermarket fridge hackers, no claim of responsibility

At least 350 supermarkets caught up in cyberattack, spoilt food disposed of Expert suggests attack exploited failure of 'basic cyber hygiene' Danish firm urges companies to use up-to-date systems (Adds update on Dutch disruption in paragraphs 2, 22-24, adds Dixell and Copeland firmware also impacted in paragraphs 7) By Raphael Satter and Gabriel Stargardter PARIS, Oct 13 (Reuters) — French investigators on Tuesday were hunting the hackers who seized control of cooling units at hundreds of supermarkets in a cyberattack that underlined the vulnerabilities of connected systems, with no group publicly claiming responsibility. The investigation comes as Dutch supermarket company Ahold Delhaize grapples with a separate cybersecurity incident that disrupted online services, although Dutch authorities said they saw no connection between the two events. The absence of a claim of responsibility by hacktivists or a ransom demand by cybercriminals has puzzled French investigators, according to a source with knowledge of the probe. Typically, such groups tend to quickly seek to monetise their hacks or claim credit for them for political ends. The cyberattack, which manually overrode the tempera