This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.
Indication of Infection
Increases in the size of .EXE files without the time/date stamp changing
Methods of Infection
This virus is a memory resident infector. Once an infected file is run on a host system, it will remain in memory and infect files throughout the system.
PE_HEZHI.A (Trend), W32.Hezhi (NAV), W32/Hezhi-A (Sophos), W32/Hezhy.A (F-Prot), Win32.Flagger (CA), Win32.Hezhi (AVP)