Attempts by cyber-criminals and hostile intelligence agencies to attack the British government have been outlined by the foreign secretary.
William Hague told a conference in Munich how government computers had been infected by a virus last year.
He also detailed an attempt to steal data from a UK defence contractor.
Mr Hague claimed cyberspace was providing "rich pickings" for criminals and urged governments to move faster to counter the threat.
In his speech, Mr Hague went into detail about some of the recent attacks to which systems in the UK have been exposed.
Some computers belonging to the British government had been infected with the "Zeus" computer virus, he said, after users had opened an e-mail purporting to come from the White House and followed a link.
Mr Hague said: "Our experts were able to clear up this infection but more sophisticated attacks such as these are becoming more common."
Defence contractors in the UK were also being targeted, the foreign secretary said, describing an attempt by someone masquerading as an employee of another defence firm to send a malicious file designed to steal information.
'Hostile state agency'
Mr Hague also said that last month three of his staff had been sent an e-mail apparently from another colleague in the Foreign Office.
In fact the e-mail was "from a hostile state intelligence agency" and contained "code embedded in the attached document that would have attacked their machine."
The foreign secretary said the e-mail had been prevented from reaching its intended targets.
"These are the kind of threats we are now facing every day," he said.
Mr Hague said these kinds of cyber-threats called for a "global response", with like-minded countries agreeing standards of behaviour on the internet.
He added that the UK was determined to be at the forefront of attempts to safeguard liberties on the net, but warned that many countries were "actively working against us in a hostile manner."