A new report from security firm Kaspersky Lab suggests that there has been little growth in the number of new malware samples over the past year.
The company reported that roughly 15 million new malware samples were found during 2009, a rate of about 30,000 a day which is "virtually the same" as the 2008 level.
While the growth of new threats levelled off, Kaspersky said that the malware that did emerge was more sophisticated and widespread.
The company noted that nine pieces of malware were able to infect more than a million systems in 2009, while sophisticated programs such as polymorphic worms became more common.
Kaspersky also reported that web-based fraud schemes, such as fake anti-virus software, boomed in 2009 and netted some US$150m in profits.
Much of the focus this year is expected to shift from PC-based malware to attacks on web services and new devices.
Kaspersky pointed to an increase in attacks targeting Facebook and Twitter over the year, and predicted that the trend will continue in 2010.
The company suggested that web services such as Google Wave could also be popular targets this year, as well as peer-to-peer services and mobile handsets.