Threat description




Trojan-Downloader:OSX/Flashback is a family of malicious applications which when installed on a computer will download a payload from a remote site, then modify targeted webpages displayed in the web browser. Variants in the Flashback family may include additional malicious functionalities or characteristics.


Free Removal Tool

11 April 2012: F-Secure now provides a free removal tool that automates the detection and removal of Flashback variants from an infected machine.

Further information and download of the tool is available in the following Labs Weblog post:

Manual Removal

Disinfection instructions for Flashback malware differ depending on the specific variant present on the machine. Please refer to the individual descriptions for each detected variant (see theTechnical Details section below) for specific removal instructions.

Technical Details

Early Flashback variants disguised themselves as Flash Player installers in order to trick users into installing and executing them.

Subsequent Flashback variants no longer use social engineering tactics to ensure distribution; instead, they are dropped by malicious Java applets exploiting known vulnerabilities, thereby requiring no user action for infection to occur.

Additional technical details are available in the following Labs technical paper: Flashback OS X Malware (PDF)

For more information, please see the individual descriptions for the variants detected:

This malware family is also further discussed in the following Labs Weblog posts:

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