Researchers have uncovered a piece of botnet malware that is capable of infecting computers running Windows, Mac OS X, and Linux that have Oracle's Java software framework installed.

The cross-platform HEUR:Backdoor.Java.Agent.a, as reported in a blog post published Tuesday by Kaspersky Lab, takes hold of computers by exploiting CVE-2013-2465, a critical Java vulnerability that Oracle patched in June. The security bug is present on Java 7 u21 and earlier. Once the bot has infected a computer, it copies itself to the autostart directory of its respective platform to ensure it runs whenever the machine is turned on. Compromised computers then report to an Internet relay chat channel that acts as a command and control server.

The botnet is designed to conduct distributed denial-of-service attacks on targets of the attackers' choice. Commands issued in the IRC channel allow the attackers to specify the IP address, port number, intensity, and duration of attacks. The malware is written entirely in Java, allowing it to run on Windows OS X and Linux machines. For added flexibility, the bot incorporates PircBot, an IRC programming interface based on Java.

The malware also uses the Zelix Klassmaster obfuscator to prevent it from being reverse engineered by whitehat and competing blackhat hackers. Besides obfuscating bytecode, Zelix encrypts some of the inner workings of the malware.