The Chada Trading Agency was a false front for the snakehead Alex Rider and ASH were trying to infiltrate. It was run by the SCORPIA executive Major Winston Yu. The trading agency were going to give ASH and Alex fake immigration papers to get into Australia.
Background
Criminal and secret service organizations always seem to have false fronts in the Alex Rider series, and the snakehead are no different. The Chada Trading Agency specializes in people smuggling, money laundering and forging false documents, usually to nearby countries such as Indonesia and Australia. The trading agency also runs Unwin Toys, a company also run by Winston Yu.
Furthermore, after it became apparent that ASIS and MI6 were fully aware of SCORPIA's latest operation, Winston Yu planned to detonate Royal Blue and, using the turmoil to soon ensue, Winston would take advantage of the Chada Trading Agency's financial interest in numerous building firms to accumulate hefty sums of money, seeing as how most of western Australia would have been destroyed, as well as all of Reef Island.