Botnets are the most significant source of malicious Web traffic for enterprises on the Internet, according to new research from ZScaler s ThreatLabz. Over the past 30 days, botnets have accounted for nearly 80 percent of the security blocks within the network. In a distant second place among security blocks, malicious URLs accounted for almost 15 percent, and in a somewhat less distant third place, antivirus accounted for just fewer than four per cent of blocks. Rounding off the list was phishing (.21%), browser exploits (.1%%), adware/spyware (.08%), WRI (.02%%), and Anonymizers (.02%)
Source: https://threatpost.com/research-botnets-most-prevalent-threat-enterprise-122911/76042/