Cyber scammers are starting to use legitimate reCAPTCHA walls to disguise malicious content from email security systems, Barracuda Networks has observed. The reCAPTCHA walls prevent email security systems from blocking phishing attacks and make the phishing site more believable in the eyes of the user.
reCAPTCHA walls are typically used to verify human users before allowing access to web content, thus sophisticated scammers are starting to use the Google-owned service to prevent automated URL analysis systems from accessing the actual content of phishing pages.
Researchers observed that one email credential phishing campaign had sent out more than 128,000 emails to various organizations and employees using reCAPTCHA walls to conceal fake Microsoft login pages. The phishing emails used in this campaign claim that the user has received a voicemail message.
Once the user solves the reCAPTCHA in this campaign, they are redirected to the actual phishing page, which spoofs the appearance of a common Microsoft login page. Unsuspecting users will be unaware that any login information they enter will be sent straight to the cyber scammers, who will likely use this information to hack into the real Microsoft account.
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