I'm not sure how to avoid this problem myself other than to just be wary, be mindful, set boundaries. Don't say yes to everything right off the bat. If they seem hurt or offended at you wanting to set those boundaries, that is a sign they're someone you should stay away from. It's difficult if you have autism or pre-existing trauma. People who've experienced abuse already are more susceptible to re-experiencing that, not because there's anything wrong with them, but more likely because they have a harder time seeing toxic vs healthy social behaviours. So for example, if you had a group of friends that bullied you, you might end up with another group of bullies because you don't know what nice people are actually like, if that makes sense. We don't know what we don't know.
I personally don't really believe in ephemeral things like pheromones or vibes. I believe it's a combination of luck of the draw--for example, being born into a preferred social group, ethnicity, class, etc--and whether we meet a list of pre-existing societal ideals. Autistic people and mentally ill people are often mistaken to be psychopaths or dangerous because of these bullshit "vibes". The "vibe" is really whether the person behaves or appears in a way that is familiar. When it's uncanny or not familiar, even by the littlest bit, that person comes off as more of a threat. The unknown is scary to us, as this is part of our survival instinct. Doesn't matter if they really are hostile or not. And it's a sad thing and it's why we have, stigma, ableism and prejudice. (Okay but there are absolutely exceptions, like Elon Musk has massively unsettling vibes. That is because he genuinely is a psychopath though and didn't have a healthy upbringing).
I deal with someone in my life who might have aspd but it's just an armchair guess, not a doctor. They pretty much devote all of their energy to causing harm and destruction, and it's been on par with living with an abusive partner. You're not alone, there's tons of folks who are stuck in hostile environments and abusive relationships--money is usually the obstacle that keeps us hostage in these situations. So we just have do what we can to take steps toward building a raft. It's not your fault to be in this situation.
Anti-social behaviour should not be confused with asocial behaviour. Introverts, shy people, autistic people get labelled anti-social, but what they really mean is asocial, which refers to them just having a preference for solitude rather than socializing. There's personality disorders that fall under the "dark triad" in psychology. These are also known known as Machiavellian personality disorders. The Wikipedia article explains it more thoroughly if you look up Machiavellianism in psychology. But it basically covers the destructive PDs, including ASPD and NPD. Not sure what the third one is, might be Histrionic PD. Some people can have more than one PD, or co-morbid mental disorders with a PD. I only know these things based on my own reading as I am something of a crazy person myself and have to know these things, the same way an asthmatic person has to know how to use their inhaler.
If this person is hurting you, you could get a security camera of some kind. You could get a baby monitor for cheap and conceal it in the space they enter. Alternatively, you could get a field camera used for hunting which is like a cheaper security camera that can be put outside, or you could get an actual security camera installed. My friend installed a security camera in their home after leaving an abusive partner. I think it was a smart decision since he was a vile person and posed as a real threat to their safety.
If they're just some rando in your life like a troll on the internet, you could report them to the mods or block them. If it's more extreme cyber bullying you're experiencing, you could screenshot and log their activity, collect the evidence and contact authorities for intervention. The Government of Canada webpage on Criminal Harassment has a detailed article on stalking, and the steps you can take to protect yourself or put an end to it. Cyber stalking can be serious if the perp is writing death threats, or if they have vital information on you- ex they have your social security number or something like that.
I don't know the context of your situation, but I'll just leave this here and hope it can help you in some way! Sorry for the info dump.
The nickname for dengue fever is the bone crusher, because of the excruciating body pain it causes. It also causes depression as a symptom. People who aren't normally depressed often report feeling incredibly low or moody during the infection. That shit is no joke, it can cause organ failure and lead to death. This is why we don't get rid of the CDC or fire the department of health.