In parallel with this, Sunbelt reports a surge in password-stealing trojans and media player threats during the month.

Most significant in June, says the firm, was a surge in detections of Trojan-Spy.Win32.Zbot.gen, a growing family of password-stealing Trojan horse programmes, which moved up from fifth place in May to second in June as a result.

On the Conficker front, like the original strain, the new Downadup variant is said to spread across a network by taking advantage of vulnerability in the Windows Server service, which allows remote code execution when file sharing is enabled.

According to the report, this particular variant of Downadup also spreads through removable drives and takes advantage of weak administrator passwords to turn off some system services and anti-malcode protection.

Tom Kelchner, Sunbelt's research manager, said that, although trojans continue to dominate the top 10, June reveals interesting trends such as a fresh wave of Conficker-based detections, suggesting that this troublesome piece of malware is on its way back.

"As we expected, malware related to the distribution and downloading of media files is also on the increase, as highlighted by the appearance of Trojan.ASF.Wimad in the top 10 for June, coinciding with the start of the FIFA World Cup", he said.

"With many of the World Cup matches taking place during work hours when users have no access to a TV, the temptation to seek out online streaming services, be they from trusted or untrusted sources, has been too strong for some users", he added.

Kelchner went on to say that, in order to avoid unnecessary malware risks, it is essential to keep clear of unknown and unproven sites offering audio and video streaming.