Hackers post phone numbers of 4.6 million Snapchat users online

Hackers have accessed 4.6million usernames and phone numbers from Snapchat accounts.

The personal information was published on the SnapchatDB website, with the last two digits of phone numbers censored.

It has since been taken down, but cached versions of the site can still be accessed.

The breach follows warnings of vulnerabilities in the smartphone app's security system.

Australian firm Gibson Security had predicted issues just days before the hack, and has since denied any involvement in it.

"We know nothing about SnapchatDB, but it was a matter of time till something like that happened," the company tweeted.

The hackers were reported to have told technology website Tech Crunch: "We used a modified version of gibsonsec's exploit/method."

Snapchat - which allows people to share pictures and short videos that can be viewed for several seconds before being deleted automatically - has seen a huge rise in popularity.

In November its founders reportedly rejected a bid of $3billion from Facebook.

The app has a feature called Find Friends, allowing users to upload contacts book to help search for people they know who use it.

In a report published before the hack, Gibson Security warned that the security shortcomings mean phone numbers could be accessed through the app.

Snapchat admitted the potential vulnerability, but said it had taken measures to protect users' data.

"Theoretically, if someone were able to upload a huge set of phone numbers, like every number in an area code, or every possible number in the US, they could create a database of the results and match usernames to phone numbers that way," the company said in a blog post last week.

"Over the past year we've implemented various safeguards to make it more difficult to do. We recently added additional counter-measures and continue to make improvements to combat spam and abuse."

But the hackers claimed the measures were not strong enough: "Even now the exploit persists. It is still possible to scrape this data on a large scale.