Form (computer Virus) - Variants

Variants

Form has a number of variants. The widely documented versions are as follows.

• Form.A is a common variant of the original, where the clicking payload occurs every day, as opposed to just the 18th.
• Form.B is a minor variant of the original, with the clicking payload set for the 18th of each month instead of the 24th. It was a rare find in the field during the mid1990s, but has since become obsolete.
• Form.C is a virtually undocumented, trivial variant of the original. It is suggested that Form.C is another minor variant of Form, except only activates in May. Like Form.B, it was documented as being discovered rarely in the wild during the mid-1990s.
• Form.D is the most common version of Form besides the original. Some reports indicate that it affects the partition table in some way. It was a somewhat common virus in 1997 and 1998.
• FormII is an undocumented variant.
• Form-Canada is an undocumented variant.