LONDON, June 27 (Xinhua) -- One of Britain's biggest advertising and marketing agencies WPP confirmed Tuesday its IT system had been hit by a cyber attack.
It was the second major cyber attack with months and came after NHS hospitals were recently disrupted by a similar attack.
The London-based advertising company said in a statement that the computer systems at several of its subsidiary companies had been affected, adding that it was "assessing the situation and taking appropriate measures".
In an internal memo to staff, one of the WPP firms said it was the target of "a massive global malware attack, affecting all Windows servers, PCs and laptops". Staff were told to turn off and disconnect all machines using Windows.
IT experts said the attack appeared consistent with ransomware described as an "updated variant" of a malware virus known as Petya or Petrwrap.
The food giant Mondelez, legal firm DLA Piper and The Danish shipping and transport giant AP Moller-Maersk, which has major facilities in Britain, also said their systems had been hit by the malware, the second large-scale cyber attack in as many months.
LegalWeek reported that DLA Piper reported phones and computers across its offices in a Britain, Europe and the Middle East had been affected.
DLA said in a statement from its London office said: "The firm, like many other reported companies, has experienced issues with some of its systems due to suspected malware."
