"sinister implications" is a correct and usable phrase in written English.
It is typically used to describe hidden or underlying meanings or consequences that are perceived as threatening, evil, or harmful. Example: The politician's innocuous statement about tax cuts had sinister implications for low-income families, revealing a hidden agenda to benefit the wealthy.
Discussion on Internet movie sites is picking over the potentially sinister implications.
Shareholders, it seems, have come to recognize the potentially sinister implications of seemingly benign corporate policies.
Western viewers may not catch all of Ms. Cao's cultural references but will grasp the playful and sinister implications of her medium.
All the reviewers picked up the sinister implications of the operation and how clumsy and inappropriate psychosurgery is for dealing with emotional and social problems.
This complementary interplay takes on sinister implications in Ms. Soderberg's two "Skystack" pieces, in which the city's pollution subtly interacts with natural weather effects.
Liane was an exquisite study of erotic nostalgia, while Rückweg carried the sinister implications that a return home equates with a loss of personal freedom.
And there was a more sinister implication, too: That the audience is not capable of fairly judging a show on its own.
The lyrical moments, even when tinged with sinister implication, provide relief from the noisy outrage ("TRUMP WANTS THUGS TO FRY," as a Post headline had it) and the inexorable police and prosecutorial work.
As we near the end of the movie, it seems the main British Isle is effectively under global quarantine -- with the sinister implication that the rest of the world likes it that way.
Throughout, Fincher's talents as a film-maker are never in question, but you can't help but wish he'd use them to interrogate rather than lend credence to Gone Girl's most sinister implication: that its regressive tale of psychosexual anxiety is less a horror story than a state-of-the-nation address.
The last Labor government reduced its entire audience and constituency to one group – "working families" – and repeated the phrase ad nauseum until it became a meaningless drone (its more sinister implication being that if you weren't "working" or in a traditional family set-up, you were an "unperson" who was not to be served by this government).
