That isn't surprising. Spam traffic has hovered in the 83 to 86 percent range for about a year. What is alarming is that spam-based malware traffic -- i.e., malware that "piggybacks" on top of (or is otherwise linked to via) spam messages -- increased dramatically last month, surging by 900 percent between August and September. At one point in September, Symantec reports, malware accounted for almost 5 percent of all spam traffic.