flashback is a form of malware designed to grab passwords and other information from users through their Web browser and other applications such as Skype. A user typically mistakes it for a legitimate browser plug-in while visiting a malicious Web site. At that point, the software installs code designed to gather personal information and send it back to remote servers. In its most recent incarnations, the software can install itself without user interaction. as per CNN
Helpful Links Regarding Flashback Trojan
A link to a great User Tip about the trojan: Flashback Trojan User Tip
A related link in the tip to a checker: Malware Checker Dowload Link
Another excellent reference on malware: Mac Malware Guide
A Google search can reveal a variety of alternatives on how the remove the trojan should your computer get infected. This can get you started.
Kaspersky Flashback Trojan Site:Flashback Trojan Detection and Removal
F-Secure Tool: Flashback Removal Tool
Also see Apple's article About Flashback malware.
Thanks for these helpful links, especially Mac Malware Guide, which helped me more than any other info.
Shame Apple doesn't provide better support for Leopard and earlier users.
I browse exclusively in User A/c that doesn't have admin rights. When in User a/c any legit executable download will ask for Admin password (in drop down box), which I don't enter when in User a/c. I do all admin (Updates) from Administrator A/c and from trusted sites (e.g. Apple, Little Snitch, Microsoft Office, Perian). If anything downloading in User a/c asks for Administrator password I abort the download (move to Trash + secure erase).
Can this Flashback Malware instal via a User a/c without admin rights, and without asking for Administrator password?