Usam file extension .Usam file extension is an extension that is used by a new variant of STOP ransomware. The ‘Usam’ variant is very similar in its characteristics to other variants of this ransomware. It also encrypts files, and then renames them, giving them a new filename consisting of their old and ‘.usam’ appended at … Continue reading .Usam file extension ransomware (Usam File Recovery Guide)