Node.js http server crashes with unknown IP address displayed - node.js

Question

I am running a Node.js HTTP server, and suddenly the following message is displayed, and the server crashes:
UPDATED ERROR LOG: (after edit)
Uncaught exception in main server
{ Error: connect ETIMEDOUT 139.99.8.126:80
at Object.exports._errnoException (util.js:1018:11)
at exports._exceptionWithHostPort (util.js:1041:20)
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1086:14)
code: 'ETIMEDOUT',
errno: 'ETIMEDOUT',
syscall: 'connect',
address: '139.99.8.126',
port: 80 }
Uncaught exception in main server
{ Error: socket hang up
at createHangUpError (_http_client.js:253:15)
at Socket.socketCloseListener (_http_client.js:285:23)
at emitOne (events.js:101:20)
at Socket.emit (events.js:188:7)
at TCP._handle.close [as _onclose] (net.js:497:12) code: 'ECONNRESET' }
This is a foreign IP address not used by us.
I tried to grep into all node modules for this IP address and see nothing.
Appears to be a hacking attempt but I have no clue where to start looking.
Any help will be appreciated. I have blocked the IP address in the firewall.

Answer 1

As per node.js docs about errors say:
ETIMEDOUT (Operation timed out): A connect or send request failed because the connected party did not properly respond after a period of time. Usually encountered by http or net — often a sign that a socket.end() was not properly called.
You should create a handler for errors, so your server won't crash:
netSv.on('error', function (error) {
if( error.message.code === 'ETIMEDOUT' ){
// mail the error with some additional data to you or do something with it
}
})