In the first three months of 2012, an average of 13 percent of North American homes with broadband Internet connections showed evidence of computer malware infection, the security firm Kindsight said.
In its first-quarter malware report, Kindsight explained that high-threat malware, such as botnets, rootkits and banking Trojans, infected more than 6 percent of homes with fixed broadband. The remaining 7 percent of North Ameican broadband households were infected with moderately dangerous malware such as spyware, adware and browser infections.
Phishing emails, especially those that appeared to come from a business or government office, remained the top attack method, Kindsight said. Many of those fraudulent emails were designed to trick victims into purchasing fake anti-virus software, or to infect computers with banking Trojans like Zeus or SpyEye that hijacked people's online bank accounts and siphoned cash from their digital wallets.
Along with phishing emails appearing to come from airlines, UPS and the Better Business Bureau, Kindsight found that messages spoofed to look like IRS notifications were especially successful scam weapons targeting home Internet users in the first three months of 2012.
Many of these tax-time phishing scams were directly tied to the BlackHole exploit kit, a malicious Russian Web app that redirects browsers to any number of dangerous websites.