Mac Defender is a distribution/variant of Rogue:MacOS_X/FakeMacdef - a family of rogue applications that affect Mac OSX. This rogue claims to scan for malware and displays fake warning messages regarding “malicious programs and viruses”. It attempts to scare the affected user into paying for the fake product by displaying adult content, fake scan results, infection messages and warnings. Earlier variants of Rogue:MacOS_X/FakeMacdef required the affected user’s Administrator password in order to successfully install on the targeted computer, but more recent variants (as of late May 2011) do not.
Rogue:MacOS_X/FakeMacdef has been distributed with several different names. The user interface and other details vary to reflect each variant’s individual branding. These different distributions of the rogue may use various installation methods, with filenames and system modifications that can differ from one variant to the next.
Installation
When distributed as MacDefender, Rogue:MacOS_X/FakeMacdef may make a number of changes to an affected system during installation, including the following:
- Adds an icon to the menu bar that displays the rogue application's status, and enables user to access the application
- Creates a login item in the Account system preferences. This enables the rogue application to launch each time the user logs in.
- Creates a number of files - the rogue gathers system information and stores the text files in the root directory, for example:
Dmem.txt – contains default disk space information
Hwuuid.txt – contains the Hardware UUID
Proc.txt – contains a list of all current running processes
See below for an example of the icon used by MacDefender:
It also scans the affected computer and gathers legitimate information from the system which is used in its fake scan results in order to appear more convincing. The following files may be created for this purpose:
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~/Library/Preferences/com.aple.sv.plist
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~ /Library/Caches/ com.aple.sv.plist
The installer uses a meta-package (.mpkg) which performs the installation of multiple packages. This package serves as a container for the malicious application. The container may generate a unique installer file for every repackage version, although this does not directly imply that the malicious application contained has been modified.
Distributed via...
While unable to spread of its own accord, the Rogue:MacOS_X/FakeMacdef installer has been observed being distributed via poisoned image search results.
Payload
Displays false/misleading malware alerts
Once installed, Rogue:MacOS_X/FakeMacdef informs users that scanning is in progress and thereafter displays a fake scan result. It attempts to scare the user by providing false infection reports, and then persuade the user to follow a recommended course of action in order to protect sensitive data (such as the affected user's credit card details). This social engineering technique is used by the rogue in order to force affected users to pay for the fake product; otherwise the installed rogue application continues to remind affected users with its scare-message campaign.
The rogue application attempts to appear as a legitimate security product by displaying the following features in its interface:
- Database update - displays a status message when appearing to load and update the database.
- Control Center – displays information such as security status, license, and feature controls.
- Scan - provides quick, normal and full scan types for the user to choose from.
- System Info – displays a list of running processes, disk and RAM memory usage and license type. This feature also appears to allow a user to kill a process.
- Settings – allows a user to set the application to run on system start. The user may also choose to enable the application to perform background scanning.
- About – provides information about the product, 24x7 email, phone and ticket support and option to purchase serial number.
See below for examples of fake alerts, dialogs and the interface displayed by Rogue:MacOS_X/FakeMacdef when distributed as MacDefender:
Visits adult websites
Rogue:MacOS_X/FakeMacdef opens the affected user’s default web browser to access adult websites. This payload attempts to convince the user that the system is infected and requires attention.
The rogue application has been observed visiting the following predetermined list of adult websites:
http://gay.porn.com
http://buy-viagra-now.net
http://fitish.com
http://www.gay.com
http://www.porn.com
http://www.freebdsmgalleries.com
Contacts remote host
Once the installation is successful, the rogue sends an installation report to a remote server using HTTP. This report may include an affiliate ID. Mac Defender also has a built-in registration engine which it uses to 'register' the product when it matches one of the following predetermined serial numbers:
1837-4164-2913
2073-2182-0724
8334-8928-9153
6241-9412-3024
4734-1427-9744
7593-5662-8323
9738-3426-1840
3248-2425-5577
5435-2648-4232
1515-8434-7756
Additional information
For more information, see the Rogue:Win32/FakeMacdef family description, elsewhere in our encyclopedia.
Analysis by Methusela Cebrian Ferrer
Take the following steps to help prevent infection on your computer:
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Enable a firewall on your computer
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Get the latest computer updates for all your installed software
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Use up-to-date antivirus software
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Use caution when opening attachments and accepting file transfers
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Use caution when clicking on links to web pages
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Protect yourself against social engineering attacks
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Use strong passwords.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software. For more information, see http://www.microsoft.com/windows/antivirus-partners/.
Use caution when opening attachments and accepting file transfers
Exercise caution with email and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.
Use caution when clicking on links to webpages
Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage with harmful content.
Avoid downloading pirated software
Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see 'The risks of obtaining and using pirated software'.
Protect yourself from social engineering attacks
While attackers may attempt to exploit vulnerabilities in hardware or software to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted computer. For more information, see 'What is social engineering?'.
Use strong passwords
Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see http://www.microsoft.com/protect/yourself/password/create.mspx.