Avast alert on hxxp://differentia.ru/diff.php & hxxp://disorderstatus.ru/order.php

Hi over there:

My notebook got infected with this malware (hxxp://differentia.ru/diff.php & hxxp://disorderstatus.ru/order.php) by using a pendrive. Since then, Avast is unable to remove it. Could anybody help me? My goal is to "erase" the infection in the notebook. How can I clean my pendrive?

Attached are the TXT outputs from FRST.txt & Addition.txt.

Thanks in advance for your help!