Victims sent to phoney site and asked to spam friends.
Scammers are exploiting interest around WhatsApp’s free voice calling feature to peddle potentially unwanted programs to naïve users, according to the security vendor Malwarebytes.
Victims are ensnared in the trap after receiving a message from another user of the messaging service, which sends them to an illegitimate domain asking them to send on the spam message before taking a survey.
Jovi Umawing, malware intelligence analyst at Malwarebytes, said: "Since WhatsApp announced the addition of its calling feature recently, it is no surprise to find others banking on this temporary craze to cash in on the unwary.
"Elsewhere, we’ve seen files publicly shared by sites claiming to be either (1) an updated version of WhatsApp, (2) a cracked version of WhatsApp for rooted devices, or (3) a cracked version of WhatsApp with data."
Once victims have been through the survey they are then offered a download purporting to enable the voice calling feature on WhatsApp, but which in fact is a malicious file.
WhatsApp began rolling out the voice calling feature last week in phases, meaning that not all users will receive the option to send voice messages until later.
Android users will be able to activate the feature through official channels when it becomes available to them, and plans for an iOS launch have yet to be outlined.