 The product received generally positive reviews praising its user interface , low resource usage and freeware license . It secured AV @-@ TEST certification on October 2009 , having demonstrated its ability to eliminate all widely encountered malware . However , it lost the certificate on October 2012 , having shown a constant decline in protection and repair scores . In June 2013 , MSE achieved the lowest possible protection score , zero . According to a March 2012 report by anti @-@ malware specialist OPSWAT , MSE was the most popular AV product in North America and the second most popular in the world , which has resulted in the appearance of several rogue antivirus programs that try to impersonate it . 
