How do I check if I'm being hacked ?

I know it's a little of topic but I got mysterious call from someone that say that they are cops and send me a file through messages that's 1kb and since then my device functioning wierdly(I reported them to the cops and opened a case and they got arrested after weeks and a lot of stuff in the court that I don't want to share ), how do I remove it /get ride of it ?(I know development but I'm not familiar with android ) by HowToHack on Reddit.com How do I check if I'm being hacked ? - I know it's a little of topic but I got mysterious call from someone that say that they are cops and send me a file through messages that's 1kb and since then my device functioning wierdly(I reported them to the cops and opened a case and they got arrested after weeks and a lot of stuff in the court that I don't want to share ), how do I remove it /get ride of it ?(I know development but I'm not familiar with android )

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