Let's Encrypt responds It was inevitable. Trend Micro says it has spotted crooks abusing the free Let's Encrypt certificate system to smuggle malware onto computers.

The security biz's fraud bod Joseph Chen noticed the caper on December 21. Folks in Japan visited a website that served up malware over encrypted HTTPS. The site used the Angler Exploit Kit to infect their machines with the software nasty, which is designed to raid their online bank accounts.

The use of encryption shields the malware from network security scanners while in transit, and the certificate helps legitimize the malicious site.