Trojan:OSX/Zweite.A, Zweite.A, OSX/Zweite.A, Trojan:W32/Zweite.A


Trojan:OSX/Zweite.A masquerades as a Safari application and when executed, can perform a variety of unauthorized actions.

Manual removal

  • Open Applications, then drag the application to the Trash
  • Open Trash in Finder, then select the action "Empty Trash"

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

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    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

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    Note You need administrative rights to change the settings.

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Technical Details

Trojan:OSX/Zweite.A masquerades as a Safari application.

There are two 'variations' of the trojan: one for Intel Macs and the other for PPC Macs. It also comes with a configurator component for both OS X (Intel) and Windows. The configurator components are detected as Trojan:OSX/Zweite.A and Trojan:W32/Zweite.A respectively.

The malware author claims this trojan is his second OSX malware (hence where the name Zweite, which is German for 'second').


Upon execution, the trojan will attempt to perform a number of actions, which are specified by a text file named 'config.txt'. These actions may be any the following:

  • Take a picture from Webcam using isightcapture
  • Shut down the system
  • Display a dialogue that asks for the admin password and stores it in a file
  • Execute a command or script