Win32/LockScreen [Threat Name] go to Threat
Win32/LockScreen.P [Threat Variant Name]
Category | trojan |
Size | 163840 B |
Aliases | Backdoor.Win32.Agent.agvr (Kaspersky) |
Trojan.Horse (Symantec) | |
Generic.BackDoor!bg (McAfee) |
Short description
Win32/LockScreen.P 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:
- %system%\w4ssl.exe (163840 B)
The trojan creates the following files:
- %system%\hk.dll (7168 B)
- %system%\sysinit.exe (24576 B)
- %system%\pdctrl32.sys (3200 B)
- %temp%\delself.bat
The trojan modifies the following file:
- %system%\userinit.exe
Installs the following system drivers:
- %system%\pdctrl32.sys (3200 B)
The following Registry entries are created:
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_WINLOGONHIDER\0000\Control]
- "*NewlyCreated*" = 0
- "ActiveService" = "WinLogonHider"
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_WINLOGONHIDER\0000]
- "Service = "WinLogonHider"
- "Legacy" = 1
- "ConfigFlags" = 0
- "Class" = "LegacyDriver"
- "ClassGUID" = "{8ECC055D-047F-11D1-A537-0000F8753ED1}"
- "DeviceDesc" = "WinLogonHider"
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_WINLOGONHIDER]
- "NextInstance" = 1
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinLogonHider\Enum]
- "0" = "Root\LEGACY_WINLOGONHIDER\0000"
- "Count" = 1
- "NextInstance" = 1
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinLogonHider\Security]
- "Security" = %hex_value%
- [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinLogonHider]
- "Type" = 1
- "Start" = 3
- "ErrorControl" = 1
- "ImagePath" = "%system%\pdctrl32.sys"
- "DisplayName" = "WinLogonHider"
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:
- user7645
Some examples follow.
Example [1.] :
Example [2.] :