Malware + Recommended

New Apple Mac Trojan Called OSX/Crisis Discovered

Posted on July 24th, 2012 by

Update – July 25, 2012 10:30AM PDT

This threat may run on Leopard 10.5, but it has a tendency to crash. It does not run on the new Mountain Lion 10.8.
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Intego has discovered a new Trojan called OSX/Crisis. This threat is a dropper which creates a backdoor when it’s run. It installs silently, without requiring a password, and works only in OSX versions 10.6 and 10.7 – Snow Leopard and Lion.

The Trojan preserves itself against reboots, so it will continue to run until it’s removed. Depending on whether or not the dropper runs on a user account with Admin permissions, it will install different components. We have not yet seen if or how this threat is installed on a user’s system; it may be that an installer component will try to establish Admin permissions.

If the dropper runs on a system with Admin permissions, it will drop a rootkit to hide itself. In either case, it creates a number of files and folders to complete its tasks. It creates 17 files when it’s run with Admin permissions, 14 files when it’s run without. Many of these are randomly named, but there are some that are consistent.

With or without Admin permissions, this folder is created in the infected user’s home directory:

  • ~/Library/ScriptingAdditions/appleHID/

Only with Admin permissions, this folder is created:

  • /System/Library/Frameworks/Foundation.framework/XPCServices/

The backdoor component calls home to the IP address 176.58.100.37 every 5 minutes, awaiting instructions. The file is created in a way that is intended to make reverse engineering tools more difficult to use when analyzing the file. This sort of anti-analysis technique is common in Windows malware, but is relatively uncommon for OS X malware.

It uses low-level system calls to hide its activities, as shown in the following images:

Intego found samples of this malware on the VirusTotal website, a site used by security companies to share malware samples. This threat has not yet been found in the wild, and so far there is no indication that this Trojan has infected users so right now the threat is considered to be a low risk. Nonetheless, Intego VirusBarrier X6 detects and removes this malware using today’s definitions. It detects the dropper component as OSX/Crisis, and the backdoor component as Backdoor:OSX/Crisis. It will also block connections with the IP address the backdoor component seeks to connect with.

Intego VirusBarrier X6 users need to update as soon as possible to get protection from this threat.

We are still analyzing the threat at this time. We will post a more in-depth analysis as we have more details.

  • Mike Myers

    How exactly does the dropper write to /Library/ScriptingAdditions/ “with or without admin permissions”? That directory is owned by root.

    • LysaMyers

      There was a character that was accidentally omitted in the path, this has now been fixed. Thanks for pointing out the discrepancy!

  • Elliot Wilen

    The post says it writes to ~/Library/ScriptingAdditions/

    That directory is owned by the user, and doesn’t require authentication to modify.

  • http://twitter.com/stevosax89 Stephen Padgett

    I have what may be a stupid question, but I’m relatively new to macs, so I’m curious:

    “With or without Admin permissions, this folder is created in the infected user’s home directory:
    ~/Library/ScriptingAdditions/appleHID/

    Only with Admin permissions, this folder is created:

    /System/Library/Frameworks/Foundation.framework/XPCServices/”

    I don’t see any folder called “appleHID” when I look in /Library/ScriptingAdditions, but I do see a folder called /System/Library/Frameworks/Foundation.framework/XPCServices/

    Does that folder mean that I’m infected? Sorry if this is an obvious answer.

  • http://twitter.com/keithkarmakaze Keith Kim

    “This threat has not yet been found in the wild…” so where was it found/made to be put into VirusTotal and have Integro X6 defend against it?

  • http://www.facebook.com/Ps3gamer17 Matthew Mclean

    Im on 10.8 n i have it i think when i go to /System/Library/Frameworks/Foundation.framework/XPCServices/ in the go menu get this aswell does it mean i have it com.apple.foundation.UserScriptService.xpc i

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