However, when Ontario.1024 is in memory, no increase in file size will be observed due to the virus' stealthing.
The WildList [2], an organisation tracking computer viruses, listed Ontario.1024 as being in the field from July 1993 to December 1998, when it was removed due to lack of a submitted sample.
Like all DOS file infectors, the advent of Windows significantly hindered the spread of Ontario.1024.
Trend Micro [3] reports 301 infections since 6 November 2000, with rates having fallen to about once every month or two by 2005.
Because of its rather extreme differences from the original virus, some vendors identify it as a member of a separate family - hence the alias Bootache.2048.
However, when Ontario.2048 is in memory, no increase in file size will be observed due to the virus' stealthing.
Ontario.2048 also features an extremely complex encryption system; a given sample of Ontario.2048 may only share two bytes in common with another.
The third is a reference to the Youngsters Against McAfee virus group, which the author had joined by this point.
Like all DOS file infectors, the advent of Windows significantly hindered the spread of Ontario.2048.
Trend Micro statistics report only two infections since November 6, 2006 [6], which indicates that the virus is now obsolete.