Archie Mitchell
Business reporter

Asos shares tumbled on Tuesday, with the company losing just under a tenth of its value on London’s stock market after being hit by the cyber attack.

Shares fell 9.56%, with analysts warning it could undermine an ongoing turnaround at the company and risk customer trust.

Dan Coatsworth, head of markets at investment platform AJ Bell, said Asos will need to “rapidly show it can fix any vulnerabilities in its systems and provide clarity on any related financial hit”.

He said it was not long ago that Marks & Spencer was “hit for six” by a cyberattack, which had a major impact on its earnings.

Tuesday’s dip comes after an otherwise positive year for Asos, with its shares still worth more than double what they were in January.

Telegram channel linked in Asos message appears to use Chinese translationspublished at 16:54 BST

16:54 BST

By Sam Howarth

BBC Verify has been looking into channels on the Telegram messaging app that appear to be linked to the push notification sent to Asos users this morning.

The notification included a link to one Telegram channel which in turn directed users to the “Xuanye Group Channel”. The channel appears to have been created today.

Its first message began “hello dears” before saying it was a “legitimate channel” and warning users to be wary of impersonation. A second message read: “Regarding ASOS, payment information is not affected.”

Four hours later, the channel posted a further message saying the Asos app was safe to use and the incident involved customer information. It added the information was “safe on our server” and would not be accessed for a "designated period". We have not been able to confirm this.

BBC Verify found the Telegram channel and account names used spellings consistent with Chinese pinyin - a system for representing Chinese characters using the Latin alphabet. It is widely used in mainland China.

The messages also include language that appears to have been translated from Chinese. The “hello dears” greeting resembles the informal Chinese expression 亲们 “qīnmen” which is commonly used online to address a group of people in a warm or familiar way.

The use of Chinese pinyin and this wording do not, on their own, establish who is behind the accounts or where the group is based.

James Kelly
Your Voice

"Initially, I thought it was a promotion or a way of catching customers’ attention for a sale," says Emily from Bristol.

The 30-year-old says she's worried she may have "affected the integrity of security" of her phone by opening the message.

"I clicked on it, but when it took me to the app’s home page, I became concerned and wondered whether it could be a way of obtaining customer information," she explains.

"I’m a regular Asos customer, but this experience may make me a little more cautious about shopping with them in the future."

Hacks of today's nature are an "awful thing" to happen to any business and have unfortunately become a part of their lives, a retail analyst has said.

Catherine Shuttleworth, the chief executive of marketing agency Savvy, says the country needs to think more about how its data and systems are being protected from hackers.

She also says customers generally understand that such attacks are outside of the brand's control, with many still trusting Marks & Spencer after last year's cyber attack.

"It's about how you recover from it, it's about how you communicate to your customers and you communicate to your staff," she says.

Katie Williams
Live reporter

Asos has just delivered an update after an "unauthorised customer notification" was sent to app users this morning. Here's what we do - and don't - know about the incident.

What we know

• Asos says it is investigating the "unauthorised activity involving third-party platforms that we use to communicate with customers"
• "Basic personal information" like name and contact details may have been accessed, but Asos says it believes payment-card information and passwords weren't impacted
• It comes after some Asos app users received a notification at around 10:00 BST this morning titled: "ASOS HACKED". Although sent to customers, it was addressed to Asos's data protection office and IT team, urging them to "engage with us" or risk a leak

• The BBC understands the National Cyber Security Centre has offered Asos its assistance - the agency supports businesses dealing with cyber-incidents

What we don't know

• Who is behind the notification, what motivated them and how they sent a notification
• Exactly what information the apparent hackers have accessed and whether there is still a risk
• How many people were impacted
• What this means for data storage company Snowflake. The unauthorised Asos notification said hackers had "fully compromised the Snowflake instance", but Snowflake subsequently told the BBC it has found "no compromise of the Snowflake platform" so far

Imogen James
Live reporter

I've been speaking to Lucy from Cumbria, who says "it was quite startling" to receive the notification.

The 21-year-old says she was concerned about "something being compromised" so went onto X to see if other people had received it.

"I saw a lot of posts about it, with quite a few saying about deleting personal information, so I went on to the app (which was working as normal) to change my details.

"I deleted all my card information, changed my password and address," she says.

Lucy also messaged her sister, telling her to do the same as she is a frequent Asos user.

"Interestingly, my sister hasn’t got the notification so I told her not to click on any notifications she gets from Asos for the time being," she told me. Lucy says her sister also lives in the UK.

When I asked her if she is now put off by using the app in the future, Lucy says: "I definitely won’t be using it until they know what exactly has been compromised.

"It will definitely make me more cautious and more likely to buy directly from the retailers that they stock instead."

Joe Tidy
Cyber correspondent

It’s still not known how many people received the pop up message but on Google’s Play store it shows that the Android app for the popular fashion and beauty company has been downloaded more than 10 million times.

Some of those people might not have app notifications turned on of course but it would make sense that millions of people would have - and so are likely to have got the apparent hacker’s message.

Apple’s Appstore does not show the number of downloads for that version of the app but it does show more than 500,000 reviews, giving us an idea of how popular it is with iPhone users.

The only people who would know for sure how many people received the pop-up notification is Asos themselves.

In a statement to the BBC, data storage company Snowflake says: "As soon as we became aware of the notification that is currently being reported, we began an investigation.

"At this time, we can report that we have found no compromise of the Snowflake platform. We take customer privacy and security very seriously," Katherine James, director of Snowflake's Europe, Middle East, and Africa communications team says.

"The investigation is ongoing and we will provide further updates as soon as more information becomes available."

As a reminder, in the pop-up notification, the apparent hackers wrote that "we have fully compromised the Snowflake instance".

We can now bring you more from the Asos statement.

The company says it is investigating the "unauthorised activity involving third-party platforms that we use to communicate with customers".

Asos also says it took "immediate action to restrict access to the notification platforms" and is working with internal and external advisers, as well as "all relevant authorities".

It says its website and app are operating "as normal, with no current disruption" to operations.

"Customer trust is incredibly important to us, and if the situation changes an update will be provided as appropriate," it says.

The company adds that it has cyber-security insurance, and says it is "too early to quantify any potential impact on trading".

Asos has just released an update following the cyber incident.

It says an "an unauthorised customer notification" was sent to customers at around 10:00 BST today.

"Basic personal information including name and contact details may have been accessed," the statement says.

It adds: "We do not believe that payment-card information or account passwords, were impacted."

We will bring you more on this shortly.

Image source, Getty Images

We've been hearing from experts over the past few hours after Asos app users received a pop-up notification that appears to have been sent by hackers. Here's what they've said:

• Reflecting on how worried Asos customers should be, the BBC's Shiona McCallum says there's currently no confirmation that customer information has been stolen
• Cybersecurity expert Jen Ellis says it is possible any attackers were trying to "apply pressure" to Asos rather than target users
• It could still be worth taking precautions, though. Another cybersecurity expert Charlotte Wilson suggests changing your password, including across other sites where it might be the same as your Asos one, and being "super cautious" about scam emails and texts
• We've also shared a list of advice - from avoiding clicking on any links in the hack notification to keeping an eye on your online transactions for anything unusual
• The BBC's Joe Tidy says it is a "bit surprising" we haven't heard anything from Asos so far - and characterises the whole incident as "really unusual" as cyber-attacks usually happen in private
• It could go down in cyber-attack history as a really significant moment, he says, calling it a "very aggressive move" to target the company so publicly

A consumer rights expert has said it is still unclear whether hackers have access to any customer data from Asos, given the organisation not yet commented on the situation.

Kat Cereda from Which? tells BBC News that under UK data protection law, customers have a right to be informed promptly if a breach has put their personal data at high risk.

She says: "Asos is legally obligated to inform you without any undue delay, explain the consequences and outline what steps they are going to be taking to protect you."

Cereda advises customers to change their passwords immediately, replacing them with strong alternatives consisting of numbers symbols and a mix of upper and lower cases characters.

The consumer rights expert also says to hang up on calls from individuals they fear may be posing as Asos or another organisation, telling them to contact the organisation themselves afterwards through separate means.

Alex Emery
Your Voice

Image source, Erin

We've been hearing from more Asos customers about the breach.

"My main concern is that my information, such as bank information, home address, telephone number, has been compromised," says Erin, a student at the University of Sheffield.

"The fact Asos have not publicly stated they are investigating, or have not offered any information on how to stay safe, is even more concerning," she adds.

Erin says that while her friends have expressed similar concerns about a potential data leak, her sister did not receive the notification on the Asos app.

"So the question is what is the extent? Are all customers affected even if they didn’t get the notification?

“It’s poor from Asos on all fronts.”

A cyber security expert says it is "virtually unheard of" for hackers to use pop-up notifications in this way, adding that the apparent attackers may be trying to "apply pressure" on Asos rather than target its users.

Jen Ellis tells BBC News the data storage company Snowflake, which is referenced in the pop-up message, is a platform that "hoovers" data from multiple sources for analysis and performing various capabilities.

She adds an organisation like Asos is "enormous" and has data about buying trends from customers around the world.

"For an attacker having access to a system like Snowflake, it's a very exciting thing because that data is gold for them. It's money basically just sitting there for them," Ellis adds.

As a reminder, Asos and Snowflake are yet to comment on the incident.

Alex Emery
Your Voice

Jodie, an analyst from Edinburgh, says she's feeling concerned after clicking the Asos notification that popped up on her phone.

"At first I thought it was an ad or a fun promotion like ‘ASOS HACKED get 50% off everything for a limited time only’," she says.

"Then I read the rest of the message which clearly showed that it wasn’t an ad and instead a message to IT.

"I clicked on it expecting maybe a message within the app itself but nothing came up. The push notification just disappeared and there was no obvious change in the account.

"It’s concerning if it is a data leak, that my address and other details may be accessed."

Chris Vallance
Senior technology reporter

The BBC understands the National Cyber Security Centre (NCSC) has offered assistance to Asos, after reports that users of its app received a notification apparently sent by hackers.

The NCSC, part of the UK's intelligence agency GCHQ, provides advice and support for the public, businesses and public sector organisations on how to defend against cyber-attacks and other information security threats.

It also supports businesses dealing with cyber-incidents and publishes guidance for individuals who believe they have been a victim of a data breach, external.

BBC presenter Pria Rai has also been speaking to the Asos chatbot function on its app.

She says that after an agent was connected to her chat, they said: "I understand you'd like to know whether the notification is genuine and whether your account may be at risk.

"I've reviewed the details and it may be a scam, however I've escalated it to our experts who are currently investigating."

Earlier, our reporter also contacted the chatbot - the agent told her that they are looking into the issue and advised her against clicking any links.

Michael Race
Business and economics reporter

Image source, Getty Images

Cyber attacks can spell huge financial implications for companies due to the huge disruption to operations by systems and data being compromised - as well as hackers typically hoping to extort a pay-off.

Those fears appear to be gathering among investors today, with shares in Asos down almost 10% following the emergence of messages on its app appearing to have been sent by hackers. The company is yet to comment.

Asos is an online retailer based in the UK and has millions of customers worldwide.

While popular with influencers and content creators advertising its products, the fashion firm has been struggling from declining sales in recent years and is in the middle of a turnaround plan aimed at returning to profit.

Ahead of its full-year results, due to be released next month, the company said there were positive signs in its recovery - however, today's news creates risk to that.

Following a cyber attack last year, M&S's profits were almost wiped out as customers were left unable to buy online from the retailer for months.

Asos will be hoping this incident will not leave long lasting damage and can be resolved as fast as possible.

Liv McMahon
Technology reporter

Image source, Getty Images

The Asos incident would appear to be the latest in a string of retail hacks and breaches that have taken place in recent years.

British brands targeted range from supermarkets like the Co-op and M&S, to carmakers including Jaguar Land Rover – with all reporting heavy sales losses in the aftermath.

Even luxury fashion retailers such as Gucci, Balenciaga and Alexander McQueen have had customer details stolen in high-profile hacks.

But few cyber criminals behind such incidents have been quite so public or direct in communicating a successful breach as these apparent hackers have here – and that’s what has really taken aback some experts, as well as our own cyber correspondent Joe Tidy.

If you're just joining us, here's a recap of what we know so far about the Asos hacking threat.

What we know:

• Late this morning, Asos customers across the UK received a notification from the retailer's app, apparently from hackers
• The notification said: "Dear Asos DPO and IT, we have fully compromised the Snowflake instance. Engage with us, or we will leak it"
• Snowflake - a data storage company - has been linked to incidents targeting services including Ticketmaster and Santander
• App users in Australia, Ireland, and France have since reported receiving the alert

• Although we haven't had an official statement from Asos yet, its chatbot says the retailer is "aware of the notification" and "investigating"
• A cyber expert has advised Asos customers not to click the link in the notification and to change their passwords

What we still don't know:

• Who is behind the hacking threat and their motivation
• Confirmation about whether any customer information has been stolen
• If Asos is a customer of Snowflake or what data, if any, is stored with the service
• The scale and seriousness of the breach