Summary

Have you been affected?

  1. Snowflake has been the subject of other high profile breaches in recent yearspublished at 11:42 BST

    Joe Tidy
    Cyber correspondent

    The company 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.

    Dan Bird, from cyber security firm Horizon3, says the pop up message apparently sent by the criminals implies their access has gone beyond the Snowflake database.

    "Sending a push notification to Asos's app users would require access to the company's notification system, which is separate from the Snowflake data platform the attackers claim to have compromised," he says.

    "If both claims hold up, it suggests the attackers got hold of credentials that opened more than one door."

  2. What is Snowflake?published at 11:34 BST

    In the pop-up message, thought to have been sent by hackers, users were told the "Snowflake instance" had been "fully compromised".

    Snowflake is a data storage company, whose popular tools have been used by dozens of firms for collecting, analysing and storing data.

    It uses the cloud, so businesses store, manage and analyse their data in the cloud, meaning no large databases are needed on site.

    This means it's easier to share data across different teams.

    Its website says there are 12,062 global customers.

  3. Dozens share image of message on social mediapublished at 11:24 BST

    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.

    It also 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.

    Screenshot of notification from Asos
    Image caption,

    Someone in the BBC newsroom received the notification - here's a screenshot from their phone

  4. Asos app users receive notification apparently from hackerspublished at 11:24 BST
    Breaking

    Asos users across the UK have been sent a notification from the retailer's app, apparently from hackers.

    A message that appeared on phone screens on Tuesday morning says: "Dear Asos DPO and IT, we have fully compromised the Snowflake instance.

    "Engage with us, or we will leak it."