Question: Who wrote the song sampled in Skinny Puppy's "Worlock"?

Context paragraphs:
CEvin Key: cEvin Key (born Kevin William Crompton, February 13, 1961) is a Canadian musician and founding member of the industrial music band Skinny Puppy.  In addition to his work with Skinny Puppy, Key has had several side projects, including Doubting Thomas, Cyberaktif, and Hilt.  After Skinny Puppy disbanded in 1995, Key's main project was electronic noise group Download, as well as some solo releases.

List of Skinny Puppy side projects: This is a list of side projects of the prominent industrial band Skinny Puppy, who have released twelve albums and toured extensively since 1982.  This list includes other projects begun by cEvin Key and Nivek Ogre—the only constant members of Skinny Puppy—since its inception.  Other members have included Dwayne Goettel, Mark Walk, Dave "Rave" Ogilvie, and many other guests/session musicians; this list does not include other projects of those musicians.

Worlock: Worlock is a single by the band Skinny Puppy from the album "Rabies".  The song uses a sample of the guitars in "Helter Skelter" by The Beatles, as well as a vocal sample of Charles Manson singing the song.

OhGr: ohGr is a industrial band formed by Nivek Ogre and Mark Walk of Skinny Puppy.  Early ohGr releases incorporated hip hop and synthpop influences, and in contrast to Skinny Puppy, utilized conventional structures and a lighter tone.  Ogre noted that this direction was inspired by the pop bands he enjoyed as a child, such as The Archies.  However, from "Devils in my Details" onwards, ohGr has taken to a more abrasive, non-linear flavour of electro-industrial.

Helter Skelter (song): "Helter Skelter" is a song by the English rock band the Beatles that was released in 1968 on their self-titled double album, often known as "the White Album".  It was written by Paul McCartney and credited to Lennon–McCartney.  The song was a product of McCartney's attempt to create a sound as loud and dirty as possible.  The Beatles' recording has been noted for its "proto-metal roar" and is considered by music historians to be a key influence in the early development of heavy metal. " Rolling Stone" magazine ranked "Helter Skelter" 52nd on its list of the "100 Greatest Beatles songs".

Tenebrae Vision: Tenebrae Vision is the only album of Canadian industrial band Cyberaktif which consisted of cEvin Key and Dwayne R. Goettel of Skinny Puppy and former Skinny Puppy member Bill Leeb of Front Line Assembly.  For "Cyberaktif", Leeb adopted his stage name, Wilhelm Schroeder, he had used while with Skinny Puppy.  The album was released in 1991 through Wax Trax!  and features Blixa Bargeld of German industrial band Einstürzende Neubauten.

Doomsday Festival: The Doomsday Festival was a two-day music festival held August 19-20, 2000, at the Ostragehege in Dresden, Germany.  The event featured a wide range of bands, but is best known as the occasion of Skinny Puppy's reunion concert, which closed the festival and was recorded for the live album "" (2001).  It was Skinny Puppy's first concert since 1992, first in Europe since 1988, and first ever in the former East Germany.  The Sisters of Mercy headlined the first day of the festival.

Download (band): Download is a Canadian electronic music group formed by Dwayne Goettel and cEvin Key of Skinny Puppy in 1994.  The initial lineup also included Off & Gone's Phil Western and Mark Spybey of Dead Voices on Air, but has since been particularly fluid, with Key and Western being the only constant members following Goettel's death.  Download's music has been described as post-industrial, drawing from the band's genesis as part of Skinny Puppy but also sharing common stylistic ground with such artists as Aphex Twin and Autechre.  The primary instrumentation common throughout their albums is a blend of synthesizers and sampled instruments; the music is particularly centered on elements of percussion and rhythm.

Nivek Ogre: Nivek Ogre (born Kevin Graham Ogilvie December 5, 1962) is a Canadian musician, performance artist and actor best known as a founding member of the industrial music group Skinny Puppy.  Since that band featured another Kevin (Crompton, a.k.a. cEvin Key) and was produced by another Ogilvie (Dave, a.k.a. Rave), Ogre's alias was practical as well as theatrical.  Since 1982, he has served as Skinny Puppy's primary lyricist and vocalist, occasionally providing instrumentation and samples.  Ogre's guttural singing style and use of costumes, props, and fake blood on stage helped to bring Skinny Puppy extensive publicity and has inspired numerous other musicians.

Skinny Puppy: Skinny Puppy is a Canadian industrial music group formed in Vancouver, British Columbia in 1982.  The group is widely considered to be one of the founders of the electro-industrial genre.  Initially envisioned as an experimental side project by cEvin Key (Kevin Crompton) while he was in the new wave band Images in Vogue, Skinny Puppy evolved into a full-time project with the addition of vocalist Nivek Ogre (Kevin Ogilvie).  Over the course of a dozen studio albums and many live tours, Key and Ogre have been the only constant members.  Other members have included Dwayne Goettel (1986–1995), Dave "Rave" Ogilvie (long-time associate, producer, and "unofficial" fourth member until 1995), Mark Walk (2003–present), and a number of guests, including Bill Leeb (1985–1986, under the pseudonym Wilhelm Schroeder), Al Jourgensen (1989), and many others.

Supporting paragraphs: Worlock Helter Skelter (song)
Answer: Paul McCartney