The report, based on in-person interviews with 354 U.S. adult Web users in September and October, found that the proportion of home computers with spyware or adware programs fell to 61 percent, from 80 percent last year.
Homes with children were particularly likely to have spyware or adware, with 69 percent of households with children reporting spyware or adware, compared to 58 percent of homes without youngsters.
In addition, ad-serving programs that rely on pop-ups are likely to be less effective this year. Seventy percent of respondents said they now block pop-up ads, up from 47 percent last year.
The survey also found that one in four U.S. Web users--23 percent--are targeted by fraudulent phishing e-mails each month. What's more, 18 percent of online users say that a friend or family member has been conned into giving phishers personal information used for identity theft.
The survey did not examine phishing last year, because the problem has only become widespread more recently, said AOL spokesman Andrew Weinstein.
Even this year, just 42 percent of those surveyed were familiar with the term "phishing"--which typically refers to a type of scam in which con artists send e-mails purporting to be from banks, credit card companies, or Internet service providers, which ask recipients to provide sensitive information, such as account numbers.