As part of a random phishing campaign, cybercriminals send fake emails represented as official WhatsApp content to spread malware when the 'message' is clicked on.
The emails are being sent from a rogue email address, disguised with an umbrella branding “WhatsApp,” but if users look at the actual FROM email address, they will see it is not from the company.
In order to spread the rogue malware and infect computers, the cybercriminals are using multiple subject lines:
- You have obtained a voice notification xgod
- An audio memo was missed. Ydkpda
- A brief audio recording has been delivered! Jsvk
- A short vocal recording was obtained npulf
- A sound announcement has been received sqdw
- You have a video announcement. Eom
- A brief video note got delivered. Atjvqw
- You’ve recently got a vocal message. Yop
Each subject ends with a set of random characters like ‘xgod’ or ‘Ydkpda’. These are probably used for encoding some data, to identify the recipient(s).
The attachment contains a compressed (zip) file, in which a malware executable resides. The malware is a variant of the “Nivdort” family. The malware usually replicates itself into different system folders, adding itself into an auto-run in the computer’s registry.
Comodo have no released information on how this malware can affect Android and un-jailbroken iPhone’s or what happens if the email is opened in an OS X or Windows device.
“Cybercriminals are becoming more and more like marketers – trying to use creative subject lines to have unsuspecting emails be clicked and opened to spread malware,” said Fatih Orhan, Director of Technology for Comodo and the Comodo Antispam Labs.
In this case it is all about social engineering and the fact that WhatsApp is a popular app on iOS and Android – it is not that WhatsApp is infected although the Chinese developed app was part of the XCodeGhost debacle last year that could infect iPhones.
WhatsApp has also been used in lots of other social engineering scams including hoax messages - all carrying malicious payloads – urging you to use the service, forward recommendations for the app to friends, reactivate your account etc.