We are not sure the extent of the hack or even certain what exactly is going on, however a report by The Next Web suggest that the Apple App Store has been hacked, and user accounts in the US and UK have been compromised.

More than 40 of the top 50 apps listed in the “Top Books Paid Software” category are from the same publisher, Thuat Nguyen. The publisher’s website is listed as the non-existant home.com. If things were not bad enough with someone hacking / manipulating the app store rankings, reading through several of the bogus app reviews and a quick search on Twitter show a number of US and UK based users reporting unauthorized charges totaling as much as $600. [The Next Web]

Because the extend of the hack is unknown, we suggest that all users change their iTunes password immediately. Better safe than sorry. Additionally, keep an eye on your email for any iTunes store receipts. For information on how to check your iTunes account for recent purchases, please see this guide.

Apple has yet to respond to the news and with this being a holiday weekend, it will likely be some time before anything is done. Once the issue is resolved, Apple will almost certainly refund users for bogus charges.

Update: There appear to be a number of different publishers / developers appearing besides Thuat Nguyen who was mentioned when we first published this story. So far, a majority of them appear to be Asian in origin and the books appear to be rip offs of other people’s work. We will continue to update as more information becomes available.

Update 2: The Next Web has put together a list of “the facts” that are known about the current situation. You can read it here.

Update 3: Apple has removed the hacker’s apps. For more information, see this post.