It is a family of nonmemory resident parasitic Windows viruses. The viruses of family are silly and have quite short size - up to one kilobyte. They are buggy and infected program in most of cases crash on start.
The "Rat.463" and "Rat.505" viruses while infecting a file overwrite the Fixup file section. The "Rat.886" virus appends its code to the end of last file section.
The viruses do not manifest themselves in any way, the "Rat.886" virus contains the text:
[Win95.TrendKiller]
[Rat Heart /ASM]
