I know that this theory might sound crazy, but hear me out. This might be one of the first theories about Mantah Corp's CEO and who he or she is, and when one gets to it, it would make a lot of sense.

We know that Mantah Corp was a genetics corporation that tried to create the first live dinosaur through genetic engineering, but they were beaten by InGen and Henry Wu. They were also the ones who threatened the Gutierrez family that if they don't send Sammy to be their spy at Camp Cretaceous, then they'll lose everything they owned, but they'd rather lose their property than use their daughter like that. However, Sammy did so anyway and contacted a Mantah Corp agent to become a spy for them. This is clearly child endangerment because Sammy was a 14-yr-old and was put in various dangerous situations alongside the other five campers.

In Season 2, we (the audience) are the only ones to notice that the signal has been received, presumably by someone outside the island. Brooklynn noticed that Eddie, a scientist working with Henry Wu, said something about "the other guys" and wondered if that could be Mantah Corp.

However, to really connect Eli Mills with Mantah Corp, we have to dig deeper. Mills is a corrupt official who has a lot of resources and is infamous for the murder of Benjamin Lockwood, but we also know that Mills has been working with Henry Wu to create the Indoraptor to sell the hybrid at his auction to make money, just like Eddie helped Wu create dinosaurs for the park Jurassic World. Mills even sent a team to grasp an Indominus rex bone to create the Indoraptor for his auction later on. Also, the aforementioned Benjamin Lockwood used to be a business partner of John Hammond, the founder of InGen, and as Mantah Corp tried to beat InGen in creating the first genetically-engineered dinosaur but failed, this could be one of the reasons why Mills hates him so much.

Now, considering everything he's done, which previously introduced character would probably have the type of heart to threaten the Gutierrez family about taking away their land and their property? Mills. Who was the man who helped Wu create the Indoraptor, not to mention that one of Wu's scientists could have been working for Mantah Corp? Mills. Who was the one who sent a team to take a bone of the Indominus rex to create the Indoraptor, following the Jurassic World Incident in which all six Camp Cretaceous campers survived? Mills. And lastly, who killed Benjamin Lockwood, the man who worked with John Hammond whose company was rivals with Mantah Corp? Mills.

All evidence we have seen thus far points to Mills pulling the strings behind Mantah Corp this whole time. Since it's evidential that Mitch & Tiff were not the ones who received the signal, and that the kids uncovered more secrets about Mantah Corp and their illegal operation (not to mention caged dinosaurs in an unknown area of the island, and dinosaurs were caged during Mills's auction, with the Ankylosaurus being sold possibly being Bumpy), I think that Mills may have actually been the one who received the signal and would be sending his men to retrieve not only the I. rex bone but the Camp Cretaceous campers as well.