Trojan-Downloader:OSX/Flashback

Classification

Malware

Trojan-Downloader

OSX

Trojan-Downloader:OSX/Flashback, Backdoor:OSX/Flashback, Exploit:Java/Flashback, Trojan:OSX/Flashback

Summary

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.

Removal

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.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

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: