Bitcoin developer Jeff Garzik said the core bitcoin block chain consensus mechanism and payment system are continuing to work as before, and are not directly impacted by transaction malleability.

He added: “Web wallets and other services that build services on top of bitcoin are reporting problems similar to MtGox, and are taking safety measures to ensure no fund loss, during this network disruption.

“Yesterday’s statement must be revised:  we will likely issue an update fixing two edge cases exposed by this attack.”