【原句】Two weeks ago the central bank announced curbs on acquiring foreign exchange, making it harder for companies to get dollars legally at the 8.28 rate to sTOP leakage of foreign currency overseas.
【疑问】不定式短语to sTOP leakage…修饰的对象是哪个？
网友已经多次就非谓语动词的修饰关系提问了。你应该可以从以前的提问和解答中总结规律，学会原则，举一反三，而不致于每次遇见非谓语动词都疑惑吧。
to sTOPleakage是句子谓语announced的目的状语。将这个不定式移至句首，依旧成立，意思不变，就是目的状语的证明。making it harderfor...是目前分词短语作结果状语。