The Chinese government has been accused of backing cyberattacks against Apple's iCloud in order to steal user data within the country, but but has denied the reports. Chinese web monitoring group Greatfire.org, reported that Apple's cloud backup and storage service was attacked by cybercriminals using a man-in-the-middle (MITM) attack, which slots a malicious website in between users and the iCloud server.

"This is clearly a malicious attack on Apple in an effort to gain access to usernames and passwords and consequently all data stored on iCloud such as iMessages, photos, contacts, etc," said Greatfire in its report.

The attack coincided with the launch of Apple's iPhone 6 handset in the country last week.

Hua Chunying, a spokeswoman for China's foreign ministry, told journalists the government was "resolutely opposed" to hacking.

China Telecom, the country's state-owned internet provider, also said the accusation was "untrue and unfounded".

Greatfire has previously reported about attacks on Google, Github and Yahoo.

In order to counteract a MITM attack, GreatFire advises internet users in China to first use a trusted browser on their desktops and mobile devices - Firefox and Chrome - in order to prevent them from accessing iCloud.com when they are trying to access a site that is suffering from a MITM attack.

In addition, using a VPN could keep them safe, along with a two-step verification for their iCloud accounts.

Apple posted a security bulletin citing the hack attempts, and indicating its cloud computing platform had not been breached.

"We're aware of intermittent organized network attacks using insecure certificates to obtain user information, and we take this very seriously," the statement said.

"These attacks don't compromise iCloud servers, and they don't impact iCloud sign in on iOS devices or Macs running OS X Yosemite using the Safari browser."

Staples under attack?

In related news, office supply superstore Staples said it was investigating possible payment card data thefts.

A blog report by security expert Brian Krebs has suggested that several of its stores in north-east America have been affected by a breach.

"Staples is in the process of investigating a potential issue involving credit card data and has contacted law enforcement," company spokesman Mark Cautela said in a statement.

Earlier this month, Sears said it had discovered that point-of-sale registers at its Kmart stores had been compromised by malicious software.