HPmal/Crusher-Y virus/spyware

Hi everyone,

    I have a problem today. the email:"

File "C:\Windows\System32\cmd.exe" belongs to virus/spyware 'HPmal/Crusher-Y': Process killed."  is sent every time when users login the computer. 

I need to research and find out causes and solutions for this problem.

I try to find the previous emails of these users which contains something like virus or spyware from flash drives, infected websites,... but I didn't see anything, just emails like that.

I search Google but the information I found is very common and I am not sure about them:

• Downloads from questionable websites
• Infected email attachments
• External media, such as pen drive, DVD, and memory card already infected with HPmal/Kovter-A
• Fake updates that trick you installing them
• Programs posing as fake virus removal tools
• Infected documents circulating on peer-to-peer (P2P) file sharing networks, torrent sites, and IRC channels

SO, anyone used to meet this problem, please tell me the main causes you found .

Many thanks,

Khang