The number of phishing websites using HTTPS has increased considerably over the past few months since Firefox and Chrome have started warning users when they access login pages that are not secure.
Internet security services firm Netcraft reported on Wednesday that, since late January, the proportion of phishing sites using HTTPS increased from roughly 5% to 15%.
One explanation for the rise is that, in late January, both Google and Mozilla implemented HTTP warnings in their Chrome and Firefox web browsers in an effort to protect their customers against man-in-the-middle (MitM) attacks.
Users of Chrome 56 and later, and Firefox 51 and later are warned when they are about to enter their credentials on a login page that does not use HTTPS. Since most phishing sites had been served over HTTP connections, cybercriminals may have realized that they need to step up their game and move to HTTPS.
“If the new browser behaviour has driven this change — and the timing suggests it might have — then it may have also had the unintended side effect of increasing the efficacy of some phishing sites,” explained Netcraft’s Paul Mutton. “Phishing sites that now use HTTPS and valid third-party certificates can appear more legitimate, and therefore increase the likelihood of snaring a victim.”
Another possible explanation, according to the expert, is that the warnings introduced by Google and Mozilla encouraged website administrators to migrate to HTTPS. Since phishing pages are often hosted on legitimate sites that have been compromised, this may have also been a factor in the significant increase of phishing sites using HTTPS.
On the other hand, Mutton pointed out that some popular browsers, such as Microsoft’s Edge and Internet Explorer, don’t display any warnings for login pages, which means phishing sites served over HTTP will still be efficient in many cases.
Cybercriminals have been coming up with clever ways to phish users’ credentials. One recent campaign aimed at Google customers leveraged a fake Google Docs application. Google quickly killed the operation, but the incident showed that malicious actors continue to improve their methods.
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