Malware is a  general category covering any type of software or program code  that may  damage computer system and/or be installed without user’s authorizations and sometimes against user’s will and/or bother users with various displayed objects and noises and/or do other damage. It is sometimes not so easy to distinguish legitimate but low-quality software from malware. That is mainly – if not only – valid for programs disguised as useful programs, normally designed to optimize the computer system and / or protect it.  The leading trend in this direction is rogue antispyware.