Eaglestar is a multi-purpose company with interests ranging from chemical production to private military contracts.
Very few places after World War II had the capability of transforming Howard Stark's formula for Molecular Nitramene into a weapon; Anton Vanko told Peggy Carter that Eaglestar was one such corporation that had the resources to do this when she brought a defused bomb to him.
Romanoff was accused of killing Russian arms dealer Mikhail Fjodorov during an undercover mission, despite the fact that Sofia, who was Romanoff's self-appointed rival, was Fjodorov's actual killer, so Romanoff was forced to flee to the hotel where she was staying.
In that hotel, she was attacked by the mercenaries, who, despite being very well equipped and having taken Romanoff by surprise, were overpowered by Romanoff, who went to interrogate one of the survivors.
- In the comics, Eaglestar International is a defense contracting firm allied with H.A.M.M.E.R.