Battle.net Accounts Compromised by Trojan

A computer Trojan is spreading that can compromise battle.net accounts and steal the account information, even for accounts protected by a Blizzard authenticator. This malware is primarily being spread in a fake version of the Curse Client, which is a popular program that updates addons for World of Warcraft. The Trojan uses a Man-in-the-middle attack to capture the login and authenticator information when a player tries to log into a Blizzard game like Diablo III, and then steals that info.

Details about the issue were posted in the World of Warcraft Customer Support forums, and the Trojan was tracked down and can be easily removed. The companies who make the major anti-virus software have been notified, and have updated their programs to catch the Trojan. Since this can affect any battle.net user, Diablo III players who do not play World of Warcraft could still be infected; there are unconfirmed reports that other programs may also be spreading the Trojan.

Here is the info from the initial post by a Blizzard Customer Support agent:
The simplest way to remove the Trojan is by using the Malwarebytes program, which eradicates many forms of malware. This is detailed in the followup Blizzard post that gives more specifics about the Trojan. This new Trojan comes to light just a few days after the 'Reaper of Souls' Phishing Scam Warning, providing another example of the lengths that unscrupulous people will go to, as they try to obtain Battle.net account info.