Firefox and Opera appear to be the browsers of choice for hackers running web sites that launch drive-by malware attacks, according to new research.

Paul Royal, a security researcher with web security service provider Purewire, is reported to have obtained the data after infiltrating the toolkits used by hackers to carry out these attacks, such as LuckySploit and UniquePack.

The research found that 46 per cent of the hackers use Firefox, while surprisingly Opera is second with 26 per cent, despite having just a two per cent market share.

Ironically, the hackers are using browsers with a smaller market share in order to avoid being hacked themselves, according to Rik Ferguson, senior security advisor at Trend Micro.

"They don't want to get compromised themselves," he said. "They stand to lose a lot - the profits of their criminal operations, control of botnets and so on - so they're looking after themselves."

However, Ferguson warned that Firefox and Opera are not intrinsically more secure than Microsoft's Internet Explorer, or other browsers, just that they have a smaller footprint and do not attract as much attention from malware writers.

As an example, Opera version 9.x currently has 22 security advisories against it and 50 vulnerabilities, 68 per cent of them highly critical, according to the latest intelligence from vulnerability scanning firm Secunia.