A third of people who use text messaging have received a scam attempt in the last six months, leaving them at risk of losing money or data, a survey has found.
Which? found that of the 34% who had received a scam message, 7% had lost personal data, money or both.
After texts, Facebook Messenger was the most common platform for messaging scams, with 16% of users having received a fraudulent message in the last six months, followed by 10% of WhatsApp users.
The most common scam claimed to be from HM Revenue and Customs, and was received by 42% of those who received a fraudulent message in the last six months.
This was followed by 34% receiving a message saying they had won a competition and 32% who were queried over an "injury claim".
Fraudulent PayPal messages were received by 29% of respondents.
HMRC announced in January that it had cut the most convincing messages reaching phones by 90%, but Which? said the latest figures suggested there was "still work to do on this issue".
Messaging scams typically aim to trick people into clicking links or calling a number to disclose personal or financial information.
Fraudsters also use "number spoofing" to make the recipient's phone display the name of an organisation instead of a number, making the fraudulent text seem like an official message.
Which? consumer rights editor Adam French said: "We found frightening numbers of people are receiving scam messages, leaving them vulnerable to the loss of their hard-earned cash and also sensitive personal information.
"Firms must take action to introduce the systems needed to stop these messages reaching people's devices.
"While we await action on this, it's important that people remain as vigilant as possible.
"Stop and think about a message you receive before engaging in communication. The problem is still rife - any unexpected messages could well be a scam."
An HMRC spokesman said: "HMRC is a trusted brand that fraudsters regularly try to exploit.
"We're aware of these scams and have a dedicated team who work with internet service providers, other Government departments and law enforcement to identify, frustrate and close down fraudulent operations.
"We use a range of technical solutions to prevent malicious messages getting through to our customers, and offer comprehensive advice to the public to help them identify genuine communications."