Java/Blacole.ET is a detection for a component of the Blackhole exploit kit - a kit used by attackers to distribute malware. Attackers install the kit onto a server, and then when you visit the compromised server, the kit attempts to exploit various, multiple vulnerabilities on your computer in order to install malware. For example, if you browsed a compromised website containing the exploit pack using a vulnerable computer, malware could be downloaded and installed onto your computer.
Typically, the Blackhole exploit kit attempts to exploit vulnerabilities in applications such as Oracle Java, Sun Java, Adobe Acrobat and Adobe Reader.
For more information on this exploit kit, and steps you can take to avoid being compromised, please see the detailed Blacole description, elsewhere in our encyclopedia.