ION starts to bring clients back online after ransomware attack - source

LONDON (Reuters) - ION, the financial trading services group hit by a ransomware attack last week, started to bring clients back on to its cleared derivatives platform overnight, a person familiar with the matter told Reuters on Tuesday.

Among the many ION clients whose operations were likely to have been affected by the attack and ensuing disruption were ABN Amro Clearing and Intesa Sanpaolo, Italy's biggest bank, according to messages to clients from both banks that were seen by Reuters last week.

The hackers who claimed responsibility for the breach at ION said last week a ransom had been paid, declining to say how much it was, or offer any evidence that the money had been handed over. ION declined to comment on whether the ransom had been paid.

(Reporting by Harry Robertson; Editing by Amanda Cooper)