Malware rating is compiled from data generated by the Kaspersky Security Network (KSN) The first Top Twenty lists malicious programs, adware and potentially unwanted programs that were detected and neutralized when accessed for the first time, i.e. by using the on-access scanner. Kido and Sality remain the runaway leaders in July’s Top Twenty. Second ranking answers two questions: Which malicious programs are most often downloaded from web pages? And which malicious programs most often infects users?”]
Source: https://securelist.com/monthly-malware-statistics-july-2009/36260/