Millions of Instagram users may have been affected by latest hack attack, social media giant warns

A group of hackers targeting A-list celebrities' Instagram accounts may have accessed millions of users' private data, the social media site has warned.

Singer Selena Gomez appeared to be one of the stars whose accounts were compromised during a cyber attack on the picture-sharing app last week.

Three naked photos of her ex-boyfriend, Canadian star Justin Bieber, were posted to her 125 million followers before her profile was shut down.

Following the hacking spree, Instagram said it believed "one or more" individuals had gained access to "a number of" stars' phone numbers and email addresses by exploiting a bug in the app's software.

The company quickly fixed the bug - but not before hackers began advertising users' private information in exchange for cryptocurrencies on the dark web.

A suspected cyber criminal claims to have accessed six million Instagram accounts and says that "Facebook/Instagram has not yet fully understood the full scope of the exploit".

Hackers provided a sample of the data to The Daily Beast, who confirmed that it appeared to include private information from high-profile Instagram accounts as well as ordinary users.

On Saturday Instagram issued a new statement confirming that the hack may have affected non-verified accounts.

"Although we cannot determine which specific accounts may have been impacted, we believe it was a low percentage of Instagram accounts," a spokesperson told Mashable.

The social media company said they thought a "low percentage" of their 700 million monthly active users could have been affected - potentially several million accounts.

Instagram co-founder Mike Krieger said: “We care deeply about the safety and security of the Instagram community, so we want to let you know that we recently discovered a bug on Instagram that could be used to access some people’s email address and phone number even if they were not public. No passwords or other Instagram activity was revealed.

“We quickly fixed the bug, and have been working with law enforcement on the matter. Although we cannot determine which specific accounts may have been impacted, we believe it was a low percentage of Instagram accounts.

“Out of an abundance of caution, we encourage you to be vigilant about the security of your account, and exercise caution if you observe any suspicious activity such as unrecognised incoming calls, texts, or emails.

"Additionally, we’re encouraging you to report any unusual activity through our reporting tools. You can access those tools by tapping the “…” menu from your profile, selecting 'Report a Problem' and then 'Spam or Abuse'.

“Protecting the community has been important at Instagram from day one, and we’re constantly working to make Instagram a safer place. We are very sorry this happened.”