Summary Trojan:Win32/Alureon.A is a data-stealing trojan. This trojan allows an attacker to intercept incoming and outgoing Internet traffic in order to gather confidential information such as user names, passwords, and credit card data. Trojan:Win32/Alureon.A may also allow an attacker to transmit malicious data to the infected computer. The trojan may modify DNS settings on the host computer to enable the attacker to perform these tasks. Therefore it may be necessary to reconfigure DNS settings after Trojan:Win32/Alureon.A is removed from the computer. Microsoft MalWare Protection Center has more info.