According to separate studies a great number of users still remain infected with PC malware even though their machines have security protections such as anti-virus software.

One study by European Union statistics agency EUROSTAT shows that 31% of PC users had malicious software in spite of the fact that 84% of users were running security apps including anti-virus, anti-spam and firewall. Besides, 3% of respondents also reported financial losses because of farming or phishing attacks, while a further 4 per cent reported privacy violations involving data sent online.

Bulgaria (58 per cent) and Malta (50 per cent) top the list of most infected users. By comparison, Finland (20 per cent), Ireland (15 per cent) and Austria (14 per cent) did relatively well.

Trojans (59.2 per cent) were the most common types of infected found on compromised PCs, followed by viruses (11.7 per cent).

A separate study by antivirus firm Panda, also published this week, says that 50% of the computers scanned by Panda in January harboured malware. As with the EU study, Trojans were the single greatest problem – accounting for 59.2 per cent of problems. Machines in Thailand, China, Taiwan, Russia and Turkey were the most commonly affected. Panda's figures come from users of its Active Scan tool.