This might be so because the removal from the OS can be problematic.
See: https://www.virustotal.com/nl/url/6db7551c0cf3d4b358cba40c81f46f2e58736f7113c2f5003a47a7580c7c3c71/analysis/1385329180/
https://www.virustotal.com/nl/file/09b6fa25cef3e3e49840849c37c1048973abf9b4f687ea996c3b41ee39402848/analysis/1384714624/
&
http://urlquery.net/report.php?id=7950380 IDS alerts given.
Flagged by scumware: 2012-04-16 20:42:41 htxp://meinelt-online.de/ramsch/tests/geschicklichkeitste
st.exe 1F299DFD2FD7C6D8F17DCD2790546359 194.116.187.22 DE W32MalwareF.NSHU
http://v.virscan.org/Application.Joke.TPE.html
pol