M&S and Co-op hacks publicly defined as a single attack - and could cost more than £400 million

Marks and Spencer store UK.

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• Cyber Monitoring Centre says it is treating M&S and Co-op attacks as a single, combined event
• M&S was hit by a major cyberattack earlier in 2025, Co-op hit weeks after
• Cost of attacks could hit as high as £440 million, CMC estimates