seo – irrelevant external links can they aggravate the Alexa ranking of a website?

It's been about a month since my website (a forum for programming issues) alexa rating is getting worse by the day and every time I check Google Analytics, the bounce rate goes up and the session time decreases each day. I should say that everything was fine until last month. The number of users and their activity are similar to those of the past. I've checked the backlinks of Google Webmaster. There are too many backlinks from pornographic websites (which are totally irrelevant to the activity area of ​​my website). Does anyone have an idea of ​​the problem and show me an answer?