A "powerful" cyberattack that started in Ukraine has spread across the world, hitting banks, government IT systems and energy firms.

British advertising group WPP said its computer networks in several locations had been targeted.

The UK's National Cyber Security Centre is investigating how many more UK firms have been hit and is "trying to get an understanding of a fast-moving situation".

:: What is the virus behind cyberattack?

Companies in six other countries were also hit, after Ukraine declared it had been struck by the biggest cyberattack in its history.


Chernobyl's radiation monitoring system is among the most serious digital networks affected. It has since been shut down, leaving employees to "go out and measure the (radiation) levels with hand-held meters".

Image: Flights faced delays at Kiev Airport, which was affected by the virus

Ukraine's interior ministry said the hack was a modified version of the Wannacry virus - a type of ransomware that crippled NHS computer systems in May.

Costin Raiu, head of global research at Kaspersky Lab, the world's biggest cybersecurity analysis firm, identified the virus as Petrwrap.

The cryptolocker demands $300 in bitcoins to let users access their data and does not name the encrypting program, which makes finding a solution difficult.

Image: British advertising agency WPP was hit by the virus

Ukraine's security council secretary said an hour after the news broke: "It is possible to talk of Russian fingerprints."

So far, companies in the following countries have been affected:

:: UK - WPP

:: US - Marck &Co, DLA Piper

:: Ukraine - Central bank, power grid

:: Russia - Evraz, Rosneft

:: France - Saint-Gobain

:: Germany - Metro, Deutsche Post

:: Denmark - AP Moller-Maersk

:: Norway - Unnamed firm

:: The Netherlands - APM Terminals

:: India - Jawaharlal Nehru container port in Mumbai

:: Australia - Two unnamed companies

News of the cyberattack emerged when Ukraine announced at around 12pm that its government IT network had been crippled by an "unknown virus".

The hack then spread, attacking several Ukranian banks, its state power grid, postal service and largest telephone firm. Kiev Airport was also hit.

A shopper at the Rost supermarket in Kharkiv took a photo of checkout computers hit by the attack, describing staff members' reaction as "frustration" and customers' as "confusion".

Some of our gov agencies, private firms were hit by a virus. No need to panic, we’re putting utmost efforts to tackle the issue 👌 pic.twitter.com/RsDnwZD5Oj — Ukraine / Україна (@Ukraine) June 27, 2017

Russian oil giant Rosneft and steel manufacturer Evraz followed, reporting they were affected by the virus.

A spokesperson for international crime agency Europol said: "Europol is aware of multiple reports in the media regarding a developing ransomware attack, we are liaising with cyber units in the member states and key industry partners to establish the full nature of this attack at this time."

The disruptions follow a spate of hacking attempts on Ukrainian state websites in late-2016 and repeated attacks on the country's power grid that prompted security chiefs to call for improved cyber defences.