H.A.M.M.E.R. is a fictional espionage and law enforcement agency appearing in American comic books published by Marvel Comics and was formed in "Secret Invasion" #8 to replace S.H.I.E.L.D., created by what two men? 
Stan Lee and Jack Kirby
H.A.M.M.E.R.
H.A.M.M.E.R. is a fictional espionage and law enforcement agency appearing in American comic books published by Marvel Comics.
 The organization is led by Norman Osborn and was formed in "Secret Invasion" #8 to replace S.H.I.E.L.D. The organization plays a large part in Marvel's "Dark Reign" and "Siege" storylines that ran from 2008 - 2010.
S.H.I.E.L.D.
S.H.I.E.L.D. is a fictional espionage, special law-enforcement, and counter-terrorism agency appearing in American comic books published by Marvel Comics.
 Created by Stan Lee and Jack Kirby in "Strange Tales" #135 (Aug. 1965), it often deals with paranormal and superhuman threats.
Cabal (comics)
The Cabal is a fictional secret society of supervillains and antiheroes appearing in American comic books published by Marvel Comics.
 The group was formed in the "Dark Reign" storyline very shortly after the Secret Invasion event. Noh-Varr
Noh-Varr is a fictional superhero appearing in comic books published by Marvel Comics.
 He first appears in "Marvel Boy" #1 (August 2000).
 He appeared in the "" and the "" limited series.
 After his appearance in "Secret Invasion", he joins the Dark Avengers as Captain Marvel.
 He joins the Young Avengers in 2013. Namor
Namor the Sub-Mariner ( ) (Namor McKenzie) is a fictional character appearing in American comic books published by Marvel Comics.
 Debuting in early 1939, the character was created by writer-artist Bill Everett for Funnies Inc., one of the first "packagers" in the early days of comic books that supplied comics on demand to publishers looking to enter the new medium.
 Initially created for the unreleased comic "Motion Picture Funnies Weekly", the Sub-Mariner first appeared publicly in "Marvel Comics" #1 (cover-dated Oct. 1939) – the first comic book from Timely Comics, the 1930s–1940s predecessor of the company Marvel Comics.
 During that period, known to historians and fans as the Golden Age of Comic Books, the Sub-Mariner was one of Timely's top three characters, along with Captain America and the original Human Torch.
 Everett said the character's name was inspired by Samuel Taylor Coleridge's poem, "The Rime of the Ancient Mariner".
 Everett came up with "Namor" by writing down noble sounding names backwards and thought Roman/Namor looked the best. God Squad (comics)
God Squad is a fictional team of gods appearing in American comic books published by Marvel Comics.
 "God Squad" is the name that the character Amadeus Cho gave to a team of gods brought together to face the oncoming Secret Invasion.
 The team was brought together in "Incredible Hercules" #117 (2008) by writers Greg Pak and Fred Van Lente, and artist Rafa Sandoval. Valentina Allegra de Fontaine
La Contessa Valentina Allegra de la Fontaine is a fictional espionage agent appearing in American comic books published by Marvel Comics.
 Created by writer-artist Jim Steranko, she first appeared in the "Nick Fury, Agent of S.H.I.E.L.D." feature in "Strange Tales" #159 (Aug 1967). X-Factor Investigations
X-Factor Investigations is a fictional detective agency appearing in American comic books published by Marvel Comics.
 The organization was created by writer Peter David for the comic book series "X-Factor" (vol.
 3).
 The agency first appears under the name XXX Investigations in the first issue of the Marvel Comics limited series "Madrox" #1 (November 2004).
 In the final issue, "Madrox" #5 (March 2005), the name is changed to X-Factor Investigations, and later abbreviated XF Investigations. S.T.R.I.K.E.
S.T.R.I.K.E., an acronym for Special Tactical Reserve for International Key Emergencies, is a fictional counter-terrorism and intelligence agency appearing in American comic books published by Marvel Comics.
 The organization often deals with superhuman threats, and was introduced in "Captain Britain Weekly" #17 as the United Kingdom's counterpart to the United States' anti-terrorism agency S.H.I.E.L.D. Maria Hill
Commander Maria Hill ( , ) is a fictional character appearing in American comic books published by Marvel Comics.
 As the former director of S.H.I.E.L.D., she appears in various storylines which often feature the Avengers or members of that group.
 She was featured in the late 2000s "Civil War" and "Secret Invasion" miniseries, and the monthly "Iron Man" series, in which she was a prominent supporting character during the "Dark Reign" and "Stark Disassembled" storylines.