A workers cleans an empty refrigerated display unit
A worker cleans a refrigerated display unit at a SuperValu branch in Ireland. The first UK impacts were reported the day after cooling units in seven European countries were hacked. Photograph: Reuters
A worker cleans a refrigerated display unit at a SuperValu branch in Ireland. The first UK impacts were reported the day after cooling units in seven European countries were hacked. Photograph: Reuters
Freezers of UK meat suppliers heat up after cyber-attacks in Europe

Cybersecurity experts say incidents had minimal effect but may represent the ‘foothills’ of a wider threat