Cleveland Police suffered a major outage after its computer systems were infected by the Conficker worm in February, ZDNet UK has learnt.
The North of England police force's main systems had to be taken offline for three days after becoming infected, Cleveland Police told ZDNet UK in response to a Freedom of Information request.
"[An] infected CD containing evidential CCTV footage [was] loaded into a standalone PC, which was inadvertently joined to the network briefly for routine maintenance," Cleveland Police said.
A Cleveland Police spokeswoman told ZDNet on Wednesday that the infection was from a Conficker variant.
Conficker is a pernicious network worm that targets flaws in Microsoft software and can spread via a number of methods, including infected USB drives and dictionary attacks on passwords over a network.
As a result of the infection, the main Cleveland Police network had to be taken offline from 17:49 on 22 February to 18:33 on 25 February.
Cleveland Police remained operational during the course of the outbreak. Predominantly administration functions were affected by the outage– Cleveland Police
Police had to use the failover network, and some frontline operations were affected, said the force.
"Cleveland Police remained operational during the course of the outbreak," said the Freedom of Information answer. "Predominantly administration functions were affected by the outage."
ZDNet UK understands that the clean-up operation took around two weeks.
In February 2010, Greater Manchester Police systems were disrupted by a Conficker infection, leading the Manchester force to disconnect itself from the Police National Computer database.
Earlier in June, police from the Ukraine, UK, US, the Netherlands, France, Germany, Cyprus and Latvia participated in raids to break up a suspected Conficker gang.
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