Altar is a memory resident parasitic Windows virus. It replicates under Win95/98 only and infects PE .EXE files (Windows executables) that are opened. While infecting the virus increases the size of last file section and writes itself to there. To stay memory resident the virus jumps to VxD mode, allocates a block of Windows memory, copies itself to there and hooks IFS API.
The virus has bugs and often halts the system. Depending on its random counter the virus erases data on C: drive - it overwrites randomly selected disk sector with the text:
[Altar] by T-2000 / Immortal Riot
The virus also contains the text string:
Awaiting the sacrifice...