Lenovo laptops automatically reinstalling crapware from the motherboard, even if crapware is deleted and clean install

so if this crapware wasn't so obvious, people wouldn't even notice it.

"computer security"


Analysis: Lenovo has sold laptops bundled with unremovable software that features a bonus exploitable security vulnerability.

If the crapware is deleted, or the hard drive wiped and Windows reinstalled from scratch, the laptop's firmware will quietly and automatically reinstall Lenovo's software on the next boot-up.

Built into the firmware on the laptops' motherboard is a piece of code called the Lenovo Service Engine (LSE). If Windows is installed, the LSE is executed before the Microsoft operating system is launched.

The LSE makes sure C:\Windows\system32\autochk.exe is Lenovo's variant of the autochk.exe file; if Microsoft's official version is there, it is moved out of the way and replaced. The executable is run during startup, and is supposed to check the computer's file system to make sure it's free of any corruption.

Lenovo's variant of this system file ensures LenovoUpdate.exe and LenovoCheck.exe are present in the operating system's system32 directory, and if not, it will copy the executables into that directory during boot up. So if you uninstall or delete these programs, the LSE in the firmware will bring them back during the next power-on or reboot.

LenovoCheck and LenovoUpdate are executed on startup with full administrator access. Automatically, and rather rudely, they connect to the internet to download and install drivers, a system "optimizer", and whatever else Lenovo wants on your computer. Lenovo's software also phones home to the Chinese giant details of the running system.

To pull this off, the LSE exploits Microsoft's Windows Platform Binary Table (WPBT) feature. This allows PC manufacturers and corporate IT to inject drivers, programs and other files into the Windows operating system from the motherboard firmware.

The WPBT is stored in the firmware, and tells Windows where in memory it can find an executable called a platform binary to run. Said executable will take care of the job of installing files before the operating system starts.

"During operating system initialization, Windows will read the WPBT to obtain the physical memory location of the platform binary," Microsoft's documentation states.

"The binary is required to be a native, user-mode application that is executed by the Windows Session Manager during operating system initialization. Windows will write the flat image to disk, and the Session Manager will launch the process."

[link to www.theregister.co.uk]