WhatsApp accused of blocking encrypted calls to Saudi Arabia by Cryptocat developer
The scam is targeting WhatsApp users in the UK Reuters

WhatsApp users in the UK are being warned to be alert to a new phishing scam that attempts to lure victims with the promise of free Sainsbury's or Topshop gift vouchers.

The scam appears as a WhatsApp message masquerading as one of the victim's contacts and encourages them to click on a web link to receive a £100 voucher from the supermarket or from other popular shops like fashion retail Topshop, according to the Independent. The messages usually appears to come from someone the victim trusts, such as a close friend or family member.

It reads: "Hey, have you heard about this? Sainsbury's is giving away £100 gift cards. They are expanding their store network and they launched this promotion. Grab a gift card while it lasts. I got mine already."

Sadly, when something sounds too good to be true, it probably is. Clicking on the link directs victims to a fraudulent Sainsbury's website where scammers are potentially able to collect personal information and install malicious software on the victim's device.

Sainsbury's said it was aware of the issue and has advised customers to delete the message.

"Scams targeting communication tools like What's App can be widely effective as users have a tendency to be less security conscious when using instant tools like this," said Leon Pinkney of Redscan.

Despite WhatsApp being an encrypted service, it is by no means impervious to cyber attacks. Last year, users were hit with scam messages inviting them to try out its then-new voice calling service. In actual fact, the messages directed victims to third-party applications capable of spreading malware if downloaded.

Twitter has also found itself being used as a conduit by cybercriminals in recent months. In September, PayPal customers were targeted by fraudulent Twitter accounts that attempted to lure them into giving up personal information, by posing as customer support staff.

How to avoid being hit by the phishing scam

"In order to protect yourself you should make sure your operating system is maintained and updated and preferably on the latest version, you also need to make sure your applications are up-to-date as well, " advises Mark James, security specialist at ESET.

"Ensure you're using a regular updating multi layered security product, this will deal with the majority of malware you encounter on a daily basis, and of course just stopping and take a breath then ask yourself 'what's the chances of this actually being real?'" James adds.

You can also report any suspicious messages you receive directly to WhatsApp, which you can do via the app's Settings menu.