Kaspersky experts have detected multiple cases of a
sophisticated scam targeting consumers through fraudulent, unsolicited Google Calendar notifications that lure them into giving away personal information. The attacks, which were observed targeting victims throughout May, abuse a specific feature of a free online calendar service that adds invitations and events to users’ calendars automatically.
Spam and phishing threats that exploit non-traditional attack vectors can be lucrative for criminals, as they can often successfully trick users who might not fall for a more obvious attack. This is particularly true when it comes to trusted legitimate services, such as email calendar features, which can be exploited through so-called “calendar phishing.”
Kaspersky observed multiple, unsolicited pop-up calendar notifications appearing for Gmail users during May. This turned out to be a result of a blast of sophisticated spam emails sent by scammers. The emails exploited a common default feature for people using Gmail on their smartphone: the automatic addition and notification of calendar invitations.
The fraud occurs when the perpetrator sends an unsolicited calendar invitation carrying a link to a phishing URL. A pop-up notification of the invitation appears on the smartphone’s home screen, and the recipient is encouraged to click on the link.
In most of the cases observed, the user was redirected to a website that featured a simple questionnaire and offered prize money upon completion. To receive the prize, the user was asked for a “fixing” payment, for which they need to enter their credit card details and add some personal information, including their name, phone number and address. Instead of being used to deliver the prize, this information went straight to the scammers who can exploit it to steal the victim’s money or identity.
“The ‘calendar scam’ is a very effective scheme, as most people have become used to receiving spam messages from emails or messenger apps,” said Maria Vergelis, security researcher at Kaspersky. “But this may not be the case when it comes to the Calendar app, which has a main purpose to organize information rather than transfer it. So far, the sample we’ve seen contains text displaying an obviously weird offer, but as it happens, every simple scheme becomes more elaborate and trickier with time. The good news is that it’s fairly easy to avoid such a scam – the feature that enables it can be easily turned off in the calendar settings.”
usa.kaspersky.com
