Variant
Individual piece of malware, sub-unit of a family
Most types of malware are subdivided into a number of families, or groups sharing many similarities, generally based on the same blocks of code and sharing similar behaviours. Within a family, a variant signifies a single individual item that is uniquely different from other members of the same family.
Variant names as displayed by anti-malware products are usually signified by letters or numbers appended after the family name - in older viruses, the length of the virus code in bytes was often adequate to distinguish it from other variants, while in recent times items tend to be given code letters from A to Z (continuing through AA to ZZ, and even AAA to ZZZ in the case of larger families), based on the order in which variants are analysed and named by virus labs.
This leads to considerable divergence in variant naming between anti-malware products, even where the family names are the same, and makes resources such as VGrep invaluable for cross-referencing purposes.
