Blizzard warned World of Warcraft subscribers on Monday that there has been a recent increase in unauthorized account logins via the website and mobile armory app. The company is currently in the process of notifying any account holders who were not using a Blizzard Authenticator and whose account showed signs of unauthorized access. Affected subscribers should expect an email soon describing how to reset their account.

"As a result of these activities, access to the World of Warcraft auction house via the mobile app has been taken off-line temporarily," the company said. "Upon request, our customer support team will restore in-game items and gold for any accounts impacted."

Blizzard's notice appeared after a number of World of Warcraft subscribers said on June 22 that the Mobile Armory had been used to fraudulently spend large amounts of their gold on extremely overpriced white-quality items on the auction house -- a way to launder gold to the posting player. The reports stemmed from both the United States and Europe, with players losing hundreds of thousands of gold. Many of these players even have Blizzard Authenticators attached to their accounts.

"This just happened to my account tonight, while I was logged in. I felt my phone vibrate so I took it out to see what it was, somehow, magically my Mobile Armory app had been opened and as I tried to swap toons on my wow account, it prevented me from logging in because my mobile armory was logging in," said one player. "In the time it took me to manually log off the mobile armory, someone had purchased Simple Wood from the AH using the mobile armory, taking me for all my gold."

"It's the mobile armory app on your smart phone. Seems they were all targeted in the night. I work graveyard shift and managed to see it happen," admitted another.

Naturally, Blizzard suggests that subscribers change their passwords periodically, and use the two-step authentication process to protect their account (SMS or Authenticator). To better protect themselves, customers are encouraged to read the company's security tips which are outlined here.