French blood storage impacted by freezer hacks as theories swirl about culprits

French authorities say that fridges used in medical facilities to store blood for donations were impacted by recent cyber-attacks by unknown hackers. The French Blood Establishment (EFS) said cold rooms storing blood were impacted by hackers, with temperatures set to rise - but staff intervened to protect blood supplies.

Meanwhile rumours have been circulating online about Russian hacktivist groups claiming they worked together to hack one of the systems that was used in the attacks which have affected European supermarkets. Noname057(16) and Z-Pentest Alliance posted that they successfully hacked Danfoss which led to speculation that they were the culprits behind the freezer hacks.

While Russian groups are not being ruled out, experts say Iranian hacktivists or nation state hackers - or even teenagers pulling pranks - could also be the culprits. Cyber-security researchers at multiple firms are pouring over evidence gathered from so-called "honeypots" to provide clues as to who is behind the waves of freezer hacks.