Happy99 (also termed Ska or I-Worm) is a computer worm for Microsoft Windows. It first appeared in mid-January 1999, spreading through email and usenet. The worm installs itself and runs in the background of a victim's machine, without their knowledge. It is generally considered the first virus to propagate by email, and has served as a template for the creation of other self-propagating viruses. Happy99 has spread on multiple continents, including North America, Europe, and Asia.
Happy99 (also termed Ska or I-Worm) is a computer worm for Microsoft Windows. It first appeared in mid-January 1999, spreading through email and usenet. The worm installs itself and runs in the background of a victim's machine, without their knowledge. It is generally considered the first virus to propagate by email, and has served as a template for the creation of other self-propagating viruses. Happy99 has spread on multiple continents, including North America, Europe, and Asia.
==Significance== Happy99 was described by Paul Oldfield as "the first virus to spread rapidly by email". In the Computer Security Handbook, Happy99 is referred to as "the first modern worm". Happy99 also served as a template for the creation of ExploreZip, another self-spreading virus.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).