TrojanDownloader:Win32/PrivacyCenter is the downloader component of Rogue:Win32/PrivacyCenter, a family of programs that claims to scan for malware and displays fake warnings of “malicious programs and viruses”. They then inform the user that they need to pay money to register the software in order to remove these non-existent threats.
We have received reports that this rogue has been distributed via poisoned search results, where users are redirected to sites that display fake scanners. These pages mistakenly report that the user's system is infected in order to convince users to download Rogue:Win32/PrivacyCenter. We have also received reports that this rogue has been distributed masquerading as a fake video codec. The pages and files utilized in this form of attack are highly variable, and change according to the user's location, browser and operating system. Please see below for an example:
Installation
Rogue:Win32/PrivacyCenter creates many files under the following subdirectories that is creates upon execution:
It modifies the registry to run its executable at each Windows start:
Adds value: "agent.exe"
With data: "%program_files%\privacy center\agent.exe"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Run
It also creates an uninstall entry for itself in the 'Uninstall or change a program' dialog. However, this (presumably deliberately) fails to function. Should a user try to uninstall the program listed as 'Privacy Center', the entry will be removed from the dialog, but the rogue will remain on the affected machine and continue to function.
Rogue:Win32/PrivacyCenter modifies the registry to replace explorer.exe under the default shell registry entry.
Adds value: "Shell"
With data: "%program_files%\privacy center\pc.exe"
To subkey: HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
This prevents Explorer and the Windows Start menu from appearing on system startup, and displays the rogue's interface instead.
Payload
Displays fake warnings
Rogue:Win32/PrivacyCenter displays fake scanning results and alerts regarding bogus malware infections and other security risks on an affected machine. Should a user attempt to 'use' Privacy Center to remove one of these bogus infections by pressing the 'Enable filter' button, they are notified that they have an out of date license, '0% Security' and several 'privacy violations'. They are then directed to a pay for licensing for a number of bogus applications. Please see below for examples of dialogs/pages displayed by Win32/PrivacyCenter:
It may also make the following registry modifications to facilitate these displays:
Modified value: "BackupWallpaper"
With data: "%systemroot%\web\wallpaper\bliss.bmp"
In subkey: HKCU\Software\Microsoft\Internet Explorer\Desktop\General
Modified value: "DeskHtmlVersion"
With data: "272"
In subkey: HKCU\Software\Microsoft\Internet Explorer\Desktop\Components
Modified value: "Source"
With data: "about:home"
In subkey: HKCU\Software\Microsoft\Internet Explorer\Desktop\Components\0
Modified value: "Type"
With data: "1"
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Ext\Stats\{72267F6A-A6F9-11D0-BC94-00C04FB67863}\iexplore
Analysis by Matt McCormack
Take the following steps to help prevent infection on your computer:
Enable a firewall on your computer.
Get the latest computer updates for all your installed software.
Use up-to-date antivirus software.
Limit user privileges on the computer.
Use caution when opening attachments and accepting file transfers.
Use caution when clicking on links to web pages.
Avoid downloading pirated software.
Protect yourself against social engineering attacks.
Use strong passwords.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
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.
You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
Use up-to-date antivirus software
Limit user privileges on the computer
Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.
You can configure UAC in your computer to meet your preferences:
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 web pages
Exercise caution with links to web pages 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.
