According to the "State of Spyware" report issued today by Webroot Software, the first three months of this year saw a "dramatic rise" in the prevalence of adware combined with a significant increase in the most malicious types of trojans and system monitors.
This malware epidemic resulted in the highest consumer infection rates since the first quarter of 2005, warning that the first quarter of 2006 saw a 15-percent jump in the share of consumer PCs infected with spyware - from 72 percent in the fourth quarter of 2005 to 87 percent in the first quarter of 2006.
The average instances of spyware on infected machines increased 18 percent over the previous quarter to 29.5 instances of spyware per infected PC, up from 24.9 instances in the fourth quarter of 2005, according to the study.
Webroot also witnessed a significant rise in trojan infection rates with an increase to 29 percent, up from 24 percent during the fourth quarter of 2005. The number of incidence of the most prevalent trojan, Trojan-Downloader-Zlob, doubled during the first quarter.
"These alarming figures illustrate that spyware is a problem that internet users are going to be battling for years to come," said C. David Moll, CEO of Webroot Software. "Spyware has proven itself as more than a simple 'flash in the pan' security threat. This is a real threat that is financially motivated and will not stop spreading. It is imperative that users protect themselves with a proven anti-spyware solution that offers superior blocking, deploys frequent updates and protects against the most dangerous types of keyloggers, system monitors and trojans."
Most surprising - and perhaps most alarming - is the dramatic rise in the prevalence of adware during the last quarter. Despite recent litigation and legislation designed specifically to thwart unlawful adware vendors, Webroot reported that the percentage of PCs with adware was 59 percent, up from 45 percent in the last quarter of 2005.
"The significant rise in the prevalence of adware should be received as evidence that adware vendors have found new channels of distribution and new infection methods, in spite of the industry's best efforts to legitimize the practice," said Moll.
Within the enterprise, the average instances of spyware on infected PCs held steady at 21.5, according to the study.
"Businesses have a serious responsibility to ensure their proprietary assets and employees' personal information is safeguarded," said Moll. "Our research shows that the most malicious types of spyware - trojan horses and system monitors - are becoming increasingly sophisticated in how they penetrate and attack networks."