Threat Encyclopedia

Selected viruses, spyware, and other threats: sorted alphabetically

Short description
Win32/LockScreen.A is a trojan that blocks access to the Windows operating system. To regain access to the operating system the user is asked to send an SMS message to a specified telephone number in exchange for a password. When the correct password is entered the trojan removes itself from the computer.
Installation
When executed, the trojan copies itself into the following location:
  • %temp%\sysstem.exe (50176 B)
In order to be executed on every system start, the trojan sets the following Registry entries:
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
    CurrentVersion\Run]
    "sysman" = "%temp%\sysstem.exe"
    "wincfg" = "%filepath%"
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Run]
    "sysman" = "%temp%\sysstem.exe"
The following Registry entries are set:
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\
    CurrentVersion\Winlogon]
    "AutoRestartShell" = 0
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\System]
    "DisableTaskMgr" = 1
    "DisableRegistryTools" = 1
Other information
The trojan displays the following dialog box:
When the correct password is entered the trojan removes itself from the computer.

The password to regain access to the operating system is one of the following:
  • imufather
  • himydarling