Win32/FakeSysdef is a family of programs that claim to scan for hardware defects related to system memory, hard drives and over-all system performance. They scan the system, show fake hardware problems, and offer a solution to defrag the hard drives and optimize the system performance. They then inform the user that they need to pay money to download the fix module and to register the software in order to repair these non-existent hardware problems. One of the first variants was distributed as program named "HDD Defragmenter" hence the name "FakeSysdef" or "Fake System Defragmenter".

System changes

The following system changes may indicate the presence of this malware:

• The presence of the following registry modifications:
  In subkey: HKCU\Software\Microsoft\GDIPlus
  Sets value: "FontCachePath"
  With data: "%APPDATA%"

  In subkey: HKCU\Software\Microsoft\Internet Explorer\Main
  Sets value: "Use FormSuggest"
  With data: "yes"

• Win32/FakeSysdef displays numerous false alerts indicating system errors while displaying the appearance of scanning the hard disk and defragmenting it, then prompts the user to buy and activate it to fix discovered errors:

  

   

  

Win32/FakeSysdef is a family of programs that claim to scan for hardware defects related to system memory, hard drives and over-all system performance. They scan the system, show fake hardware problems, and offer a solution to defrag the hard drives and optimize the system performance. They then inform the user that they need to pay money to download the fix module and to register the software in order to repair these non-existent hardware problems. One of the first variants was distributed as program named "HDD Defragmenter" hence the name "FakeSysdef" or "Fake System Defragmenter".

Win32/FakeSysdef has been distributed with several different names or aliases. The user interface and some other details vary to reflect each variant's individual branding.

The branding strategy may look legitimate to computer users as the names are usually a combination of technical words such as "HDD", "Disk", "Memory" and action words such as "Scanner", "Defragmenter", "Diagnostics", "Repair", and "Fix". Currently observed variants of FakeSysdef include the following:

• Check Disk
• Data Restore
• Data_Recovery
• Data Recovery
• Defragmenter
• Disk Defrag
• Disk Doctor
• Disk Helper
• Disk OK
• Disk Optimizer
• Disk Recovery
• Disk Repair
• Disk Tool
• Easy Scan
• Fast Disk
• File Recovery
• Full Scan
• Good Memory
• HDD Control
• HDD Defragmenter
• HDD Diagnostic
• HDD Fix
• HDD Low
• HDD OK
• HDD Plus
• HDD Repair
• HDD Rescue
• HDD Scan
• HDD Tools
• Hard Drive
• Hard Drive Diagnostic
• Memory Fixer
• Memory Scan
• Memory optimizer
• My Disk
• PC Repair
• Quick Defrag
• Quick Defragmenter
• Scan Disk
• Scanner
• Smart Defragmenter
• Smart HDD
• S.M.A.R.T. Repair
• SMART Check
• S.M.A.R.T. Check
• System Defragmenter
• System Diagnostic
• System Repair
• Ultra Defragger
• Win Defrag
• Win Defragmenter
• Win Disk
• Win HDD
• Win Scan
• Win Scanner
• Windows Diagnostic
• Windows Disk
• Windows Fix Disk
• Windows Recovery
• Windows Repair
• Windows Restore
• Windows Safemode
• Windows Scan
• Windows Tool

Some variants also use the operating system in its brand:

• Windows Fix (for example, "Windows XP Fix", "Windows Vista Fix", "Windows 7 Fix", and so on)
• Windows Recovery (for example, "Windows XP Recovery", "Windows Vista Recovery", "Windows 7 Recovery", and so on)
• Windows Repair(for example, "Windows XP Repair", "Windows Vista Repair", "Windows 7 Repair", and so on)
• Windows Restore(for example, "Windows XP Restore", "Windows Vista Restore", "Windows 7 Restore", and so on)

Installation

The Win32/FakeSysdef installer may arrive in the computer with various file names. When run, the installer drops and injects a DLL file (or sometimes and EXE file) into common processes, for example "EXPLORER.EXE", "WINLOGON.EXE", and "WININET.EXE".

In some instances, the main executable drops both DLL and EXE components. In this case, the EXE is set to run at every Windows restart and the DLL is injected into "EXPLORER.EXE" by the "EXE" component.

To ensure that it automatically runs every time Windows starts, it drops a copy of itself or its EXE component using a random file name into the %APPDATA folder.

Some variants also create shortcuts on the Desktop and in the Start Menu using the following naming format:

• %USERPROFILE%\Desktop\<FakeSysdef brand name>.lnk
• %USERPROFILE%\Start Menu\Programs\<FakeSysdef brand name>
• %USERPROFILE%\Start Menu\Programs\<FakeSysdef brand name>\<FakeSysdef brand name>.lnk
• %USERPROFILE%\Start Menu\Programs\<FakeSysdef brand name>\Uninstall <FakeSysdef brand name>.lnk

The shortcut file may look similar to the following:

The Start Menu entry may look similar to the following:

The Task Bar icon may look similar to the following:

Some variants may also create entries in the registry that allow their dropped copy to run every time Windows starts, for example:

In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Sets value: "<random string>"
With data: "%APPDATA%\<FakeSysdef copy.exe"

Win32/FakeSysdef variants also create the following registry modifications:

In subkey: HKCU\Software\Microsoft\GDIPlus
Sets value: "FontCachePath"
With data: "%APPDATA%"

In subkey: HKCU\Software\Microsoft\Internet Explorer\Main
Sets value: "Use FormSuggest"
With data: "yes"

Some variants delete the currently running FakeSysdef file after it has performed its malicious routine, as with the PC Repair variant, which drops the following file then deletes it after successful installation:

%COMMON_APPDATA%\<FakeSysdef_file name>.exe - for example, C:\Documents and Settings\All Users\Application Data\3CKFqz6zlpzK.exe

Payload

Modifies browser settings
Win32/FakeSysdef modifies several Internet Explorer settings, such as the following:

Enables submitting non-encrypted form data:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
Sets value: "1601"
With data: "0"

Changes the setting for certificates used:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\WinTrust\Trust Providers\Software Publishing
Sets value: "State"
With data: "146944"

Enables changing the desktop wallpaper:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop
Sets value: "NoChangingWallPaper"
With data: "0"

Displays all shortcuts:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
Sets value: "HideIcons"
With data: "0"

Disables Task Manager:
In subkeys:
HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
Sets value: "DisableTaskMgr"
With data: "1"

Disables checking for signatures on downloaded programs:
In subkey: HKCU\Software\Microsoft\Internet Explorer\Download
Sets value: "CheckExeSignatures"
With data: "no"

Disables marking file attachments by using their zone information:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Attachments
Sets value: "SaveZoneInformation"
With data: "1"

Sets low risk file types:
In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
Sets value: "LowRiskFileTypes"
With data: "/{hq:/s`s:/ogn:/uyu:/dyd:/c`u:/bnl:/ble:/sdf:/lrh:/iul:/iulm:/fhg:/clq:/kqf:/`wh:/lqf:/lqdf:/lnw:/lq2:/l2t:/v`w:/rbs:"

Terminates or blocks programs
Some Win32/FakeSysdef variants that may terminate running processes during installation and may block launched application after the computer restarts. During the installation process, they may terminate all running processes and force the computer to restart.

After the restart, FakeSysdef attempts to block every launched program, and may then display fake error messages offering to fix the problem. It then repeatedly restarts the computer until the user agrees to buy the fake software.

Displays fake warning messages
When run, Win32/FakeSysdef may display fake messages indicating that the computer has various performance and stability issues. The fake program interface may look similar to the following:

Some of the fake error messages that it displays may look similar to the following:

When the "Fix Errors" button is selected, FakeSysdef pretends to scan and defragment the hard disk. It then displays more fake error messages, and tells the user that he needs to purchase an "Advanced Module" for the fix. If the user chooses to do so, the browser opens. It will open a custom web browser where the user can input his credit card information to buy the software:

Connects to a remote server
Win32/FakeSysdef connects to certain servers to inform them that a computer has been infected. Some of the servers that Win32/Fakesysdef is known to connect to are:

• asha<removed>.com
• click<removed>.org
• beaut<removed>.com
• media<removed>.com
• search<removed>.org
• find<removed>.org

Analysis by Shawn Wang and Rex Plantado

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 webpages.
• 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.

• How to turn on the Windows Firewall in Windows 7
• How to turn on the Windows Firewall in Windows Vista
• How to turn on the Windows firewall in Windows XP

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. Instructions on how to download the latest versions of some common software is available from the following:

• Microsoft Malware Protection Center - Updating Software

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.

• How to turn on Automatic Updates in Windows 7
• How to turn on Automatic Updates in Windows Vista
• How to turn on Automatic Updates in Windows XP

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, such as Microsoft Security Essentials, that is updated with the latest signature files. For more information, see http://www.microsoft.com/windows/antivirus-partners/.

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:

• User Account Control in Windows 7
• User Account Control in Windows Vista
• Applying the Principle of Least Privilege in Windows XP
• More on User Account Control

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.

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

• Microsoft Security Essentials
• Microsoft Safety Scanner
• Windows Defender
• Microsoft Windows Malicious Software Removal Tool

Additional instructions to remove Win32/FakeSysdef from your computer are available here:

How to remove the PC Repair virus

For more information on antivirus software, see http://www.microsoft.com/windows/antivirus-partners/.

Additional remediation instructions for Win32/FakeSysdef:

This threat may make lasting changes to a computer's configuration that are NOT restored by detecting and removing this threat. For more information on returning an infected computer to its pre-infected state, please see the following article/s:

• Configuring Security Zone settings for Internet Explorer:
  • For Windows 7: http://windows.microsoft.com/en-us/Windows7/Change-Internet-Explorer-Security-settings
  • For Internet Explorer 7 and 8 in Windows Vista: http://windows.microsoft.com/en-us/windows-vista/Change-Internet-Explorer-Security-settings
  • For Internet Explorer 6: http://support.microsoft.com/kb/174360
• Enabling Task Manager:
  • For Windows Vista: http://windows.microsoft.com/en-us/windows-vista/Troubleshoot-Task-Manager-problems
  • For Windows XP: http://support.microsoft.com/kb/913623/
• For other support and help related articles, go to:
  • Windows 7: http://support.microsoft.com/gp/windows7
  • Windows Vista: http://support.microsoft.com/ph/11732
  • Windows XP: http://support.microsoft.com/ph/1173
• Microsoft Security TechNet Center: http://technet.microsoft.com/security/default.aspx