A second security firm took a shot at estimating how many Macs are infected by the Flashback malware and it arrived at the same conclusion as the first—more than half a million machines. That figure, documented in a Kaspersky Lab blog post published on Friday, would mean Flashback has infected slightly more than 1 percent of the 45 million Macs in existence.
Kaspersky Lab Expert Igor Soumenkov said researchers arrived at that number by registering a domain name used as a fallback command and control channel and logging the number of machines that reported to it. In less than 24 hours, a total of 600,000 unique bots connected to their server. Because Flashback shows the universally unique identifier of each bot, he said they're confidant they didn't count the same one multiple times, although they couldn't rule out the possibility that some of the machines were running FreeBSD, Linux, Windows, or other operating systems.Continue reading: Half-million Mac infection estimate backed by new analysis