hello,
There are software uses undetected exploit (0 day ) to download malware on many pc's.
name of the software: Ultrasurf.
website of the software :
ultrareach.com/
download:
http://www.ultrareach.com/downloads/ultrasurf/u992.exe
this software marked as clean by most AV companies including avia and kaspersky, symantec marked it as Suspicious.Insight
but when the user used that software to visit any payment page, it downloads many malware using undetected internet exploits ( 0 day ) .
i get keylogger from ultrasurf.
Thanks.
Best Regads.