The MSS vowed on Wednesday to “resolutely protect the nation’s strategic interests and core secrets”.
It warned the CIA that “any attempt to incite betrayal among the Chinese people is doomed to fail, and any plot to infiltrate China for intelligence will prove futile”.
The intelligence agency’s diatribe was among the top trending items on China’s X-like Weibo platform on Wednesday, with users mocking the alleged job ads.
“Can we organise a group of scammers to carry out a telecom fraud against the CIA? We can trick the US and make a little money at the same time,” one wrote.
The United States and China have long traded accusations of espionage.
In April, security officials said they had implicated three US “secret agents” in cyberattacks during February’s Asian Winter Games in the northeastern city of Harbin.
The MSS said in March it had sentenced to death a former engineer for leaking state secrets to a foreign power.
