Commtouch also determined in its multiyear study that spam and viruses follow a cyclical pattern, with a tendency to increase during the month of July. That increase is markedly higher than in previous years, accounting for a 43 percent rise over 2004.
Following closely behind pharmaceutical spam comes financing at 18 percent and sex enhancement products at 15 percent.
In one of the more surprising findings, the study determined that porn spam now accounts for only nine percent of spam received by users, down 19 percent from the prior month. Other spam monitoring firms have clocked porn spam at an even lower and rapidly shrinking percentage.
In June, Clearswift said that porn only accounted for five percent of all spam, with a laundry list of other industries crowding inboxes soliciting products that range from hair thickening creams to Christian dating sites.
"Spam volumes have held steady during the past few months," said Commtouch Director of Product Marketing Oren Drori. "However, there has been a large increase in the past year marked by 30 percent more spam outbreaks in the second quarter than during the same period last year."
July also was the peak for the highest recorded level of phishing emails in a given month, up 16 percent from the previous year. However, the number of virus-infected messages declined 20 percent in July of this year, compared to a year ago.
In other findings, Commtouch determined that China leads all other countries as the biggest producer of spam, followed by South Korea at 17 percent and the United States at 15 percent.
Seoul takes the lead on all other nations as having the most bot-infected PCs, according to Symantec, which puts that number at around four percent. South Korea is followed by U.K. cities London and Winsford, then Toronto, and finally New York.
However, many virus firms warn that August is typically the month when the heavy-hitting viruses wreak havoc. This time last year the world got its first taste of viruses like Bagle.AH, Mydoom.N and Bagle.AM. Previous August introductions have included Sircam, CodeRed, Minmail, Sobig.f and Blaster.
Commtouch’s Spam Detection Center analyzes 1.5 billion messages each month.