Strange Requests broke my nginx server

Since the last month I am developing a Node.js application with Vue.js and recently, I bought a server and uploaded my still in development site there. I deployed my test application to the server just one week ago and yesterday, I noticed a strange 504 Gateway error. Hmm…strange! Upon googling, I found out that the 504 Gateway Timeout error is an HTTP status code that means that one server did not receive a timely response from another server that it was accessing while attempting to load the web page or fill another request by the browser. I checked my backend and it is working fine, for my other server too.

I am running [NGINX] (https://www.nginx.com/) web server and decided to look at the access and error logs. I saw some strange requests which look like hacking attempts by a bot. There are a lot of http requests and most of them are served with a 404 error. A preview of the requests is here:

It looks like the bot is trying to access the server files using http. I still don’t know what exactly happened, but, these request broke my server and perhaps installed a worm or a malware on the system too. For now, I have redeployed my application and blocked all http requests, as the requests are mostly http based. SSL is already configured on my server.

The closest thing I found is this answer on Stackoverflow, which also says that they are automated attacks. I have to do some digging, if anyone has any clue, please do write in the comments. I will post an update on my blog, of what I find.