WhatsApp users are being warned about a ‘nasty scam’ in which fraudsters are attempting to take over people’s accounts.

Consumer group Which? says there has been another uplift in the number of people reporting verification code scams and here’s what users must look out for:

How does it work?

The WhatsApp verification scam will begin when you’re sent an unexpected – but genuine text from WhatsApp giving you a verification code.

These codes are usually triggered when you use the app for the first time, after you’ve logged out or if you're using a new device. However in this case the code has been generated because a fraudster has entered your phone number into WhatsApp themselves to begin trying to get access to your account.

Next you’ll receive a WhatsApp message that’ll appear as if it is coming from one of your contacts usually with a story that explains why they need that verification code you've just been sent.

Because the message looks like it’s coming from a parent or friend, trying to convince you that they’ve entered your number by mistake, many people says Which? are being instantly tricked into handing over the code.

But this is in turn is giving fraudsters open access to their accounts.

What do the fraudsters want?

Once in your account, says Which?, they may use it in a number of different ways.

Dipping into your message history will help fraudsters work out who your closest contacts are – and they could then ask them for money or sensitive information.

Sifting through old messages could also lead them to more of your personal details or information – that might be used to access other accounts you own and target you with more scams, or even blackmail you.

Having unlocked your contacts, the scam is likely to continue with fraudsters using the new set of contacts they’ve now got to gain entry to even more WhatsApp accounts by tricking another group of people.

How can I keep my account safe?

Don’t ever share your details, login information or verification codes with anyone – not even your closest family and friends regardless of how genuine a story might sound.

It is also advisable, says Which?, to install two-step verification processes at every stage possible.

Always report spam messages or block the sender of such a message within WhatsApp – you can also press and hold the message in order to report it as well.

Be wary of messages requesting money – even if they look as if they’re coming from one of your contacts. If you’re not sure – and in order to double check – give the friend or relative a quick call before handing over any money.

And if you think you’ve given sensitive details to possible fraudsters let your bank know immediately while WhatsApp users who have lost access to their accounts should email support@whatsapp.com for help.

If you have been a victim of fraud or cyber crime it should also be reported to Action Fraud via its website or by calling 0300 123 2040.