Ransom:Win32/Lyposit.B

This ransomware prevents you from accessing your computer. It covers your entire desktop with an image pretending to be from your local authorities, asking you to pay a fine to regain access. The image covering the desktop is downloaded from a certain website.

Installation

When run, it drops a copy of itself as a randomly named file in the following folders:

• %ALLUSERSPROFILE%\Application Data
• %LOCALAPPDATA%

For example:

C:\Documents and Settings\Administrator\Local Settings\Application Data\rttevjmgloi.exe

It creates the following registry key so that its copy automatically runs when Windows starts:

In subkey: HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
Sets value: "Shell"
With data: "explorer.exe, %ALLUSERSPROFILE%\Application Data\<malware file name>"

It creates the following registry key as part of its installation process:

In subkey: HKCU\Software\Microsoft
Sets value: "AutoRun"
With data: "%ALLUSERSPROFILE%\Application Data\<malware file name>"

It then forces your computer to restart so that it automatically runs.

Payload

Blocks computer access

It prevents you from accessing your computer, as it displays an image that covers your entire desktop. The image contains instructions and information about paying a fine for you to regain access to the computer. The image may look similar to the following:

If your IP address is located in France:

If your IP address is located in Germany:

If your IP address is located in Spain:

If your IP address is located in Switzerland:

It downloads this image from a certain website. Lyposit has been known to download images from the following:

• hali<blocked>were.org
• iwhf8<blocked>fueuofbejkh.org
• n8efhi<blocked>ifhuenfe.com
• neufb<blocked>jefnike.com
• urla<blocked>purla.org

If the website where it downloads the image from is unavailable, it displays the following instead:

Disables Task Manager

It prevents you from accessing Task Manager by modifying the following registry entry:

In subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
Sets value: "DisableTaskMgr"
With data: "1"

Closes all windows

It monitors your computer for all open windows on the desktop. It then closes all windows except for its own process.

Analysis by Zarestel Ferrer