Asos users across the UK have been sent pop-up messages from its app that appear to have been sent by hackers trying to extort the company.

Dozens of people have told the BBC about receiving a strange message from the clothing and beauty store's app, appearing on their phone screens.

"Dear ASOS DPO and IT, we have fully compromised the Snowflake instance. Engage with us, or we will leak it," the message reads.

Asos did not immediately respond to the BBC's requests for comment.

On social media, dozens of people have posted about receiving the message – confused as to what it means.

Although the apparent extortion message has been issued directly to customers, it is addressed to Asos' data protection officer (DPO) and IT team.

The message claims the unnamed hackers have "fully compromised the Snowflake instance".

It refers to the data storage company Snowflake, whose popular tools have been used by dozens of firms for collecting, analysing and storing data.

It is not known if ASOS is a customer of Snowflake or what data, if any, is stored with the service.

But Snowflake has been the subject of many high profile data breaches in recent years and has been linked to incidents targeting services including Ticketmaster and Santander.

It is, however, unusual that any potential data breach would be revealed quite so publicly – and for customers to be informed in this manner.

Most extortions and negotiations by cyber criminals are conducted in private, with hackers hoping their discretion will result in a quiet pay-off.

"If confirmed, this is a deeply serious attack because the hackers appear to have done something particularly brazen: turned ASOS's own app into their ransom note," says Charlotte Wilson, head of enterprise at cyber-security firm Check Point.

"Millions of people trust notifications from apps on their phones because they are supposed to come directly from the company."

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