This virus overwrites the beginning of COM files, placing the original code in encrypted form at the end. EXE files are also infected in an unusual way - the original CS:PC is not changed, but the first 5 bytes of the program code are overwritten with a FAR CALL to the virus code.
Disinfection & Removal
Variant:Voronezh-370, Voronezh-600, Chemist
Related viruses, but somewhat shorter, and with a less complex structure - probably older variants. They are only able to infect COM files, not EXE files like the 1600 byte variant.