AVDefender 2011 is a variant of
Rogue:Win32/FakePowav, which is 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 in order to remove these non-existent threats.
Installation
When run, the AVDefender 2011 variant of Rogue:Win32/FakePowav drops an executable file with a random name to a randomly generated subfolder in the "%AppData%" folder. For example, one sample creates the following file:
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%AppData%\yxuxkqaa\dthsgk.exe
It also creates a file named "installparams.lst" or "sk.lst" in the same folder.
It also creates the following files:
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%AppData%\avdefender2011vlc.dat
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%AppData%\history.dat
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%AppData%\result.dat
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%AppData%\AVDefender2011.ini
It also creates a shortcut link to its main executable as the following:
<startup folder>\avdefender2011\avdefender2011.lnk
Note: <startup folder> refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the Startup folder for Windows 9x, Me, NT, 2000, XP and 2003 is '%USERPROFILE%\Start Menu\Programs\Startup'. For Windows Vista and 7, the default location is '%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'.
AVDefender 2011 uses the following icon:
Payload
Displays fake scanner
When AVDefender 2011 is first run, it displays the following popup from the system tray:
It then launches a fake scanner, which may display popups and other windows similar to the following:
While it is scanning, or reporting a detection, it may gray out the background and prevent access to other applications on the computer:
AVDefender 2011 may also terminate other processes running on the system and display a dialog such as the following:
If the user attempts to remove any of the reported items, AVDefender 2011 may display a message such as the following:
If the user attempts to purchase the full version of the malware, AVDefender 2011 may open the browser to a webpage that has a banner similar to the following:
Analysis by David Wood
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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Limit user privileges on the computer.
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Use caution when opening attachments and accepting file transfers.
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Use caution when clicking on links to webpages.
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Avoid downloading pirated software.
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Protect yourself against social engineering attacks.
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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 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.
