These are not dangerous nonmemory resident encrypted parasitic viruses. They search for EXE files in current and parent directories, then write themselves to the end of the file. "Opic.745" infects files on C: drive only.
Depending on the system date and time the viruses beeps by the PC speaker. The "Opic.727" virus then creates two subdirectories: "Odessa!" and "Opic" and writes to the end of CONFIG.SYS file the text:
REM-Odessa Virus (c) Opic [CodeBreakers 98]
The "Opic.745" virus also contains the text:
Odessa.B (c) Opic [Codebreakers 1998]
