masscan_as_a_service VS masscan

I use this approach for monitoring open ports in our infrastructure -- running masscan, commiting results to git repo. If there are changes, open the merge request for review. During the review, one would investigate the actual server, why there was change in open ports.

https://github.com/bobek/masscan_as_a_service

We typically use a variant of https://github.com/bobek/masscan_as_a_service

Massacan is awesome. One of the usecases is to periodically scan your own servers to see if you have not accidentally opened some new ports in firewalls.

https://github.com/bobek/masscan_as_a_service

It's a nice dream of "owning" the attackers but it doesn't have a real security value.

[1] https://github.com/robertdavidgraham/masscan

A lot of these seem to use zmap (https://github.com/zmap/zmap) or massscan (https://github.com/robertdavidgraham/masscan) for the initial scan.

Often with default parameters such as zmap setting ip id to 54321, having tcp initial window at 65535, having no SACK bit set and masscan with no SACK bit either, tcp initial window at 1024, tcp maximum segment size 1460 (which is strange to put below initial window size!), (older versions having fixed src port 61000 or 60000 from documentation examples and no MSS set), all of which are extremly uncommon in legitimate traffic and thus easily identified.

Even those so called "legitimate" scanners (emphasis on the "") seem to use these tools with little or no extra configuration.

Can I get banned for mass scanning with https://github.com/robertdavidgraham/masscan or does it slow down any other vms from other persons?

Nope, this doesn't work any more. Shodan checks all ports (so any attackers using data from Shodan already know which ports you have open), and tools like masscan (https://github.com/robertdavidgraham/masscan) let you portscan the entire IPv4 address space in less than 10 minutes.

https://github.com/LogoiLab/mcsl https://github.com/robertdavidgraham/masscan

Changing the default port does nothing for security. It only prevents some basic brute force or default password scripts. Anyone is able to scan for it in no time anyway (https://github.com/robertdavidgraham/masscan).

But it should blow away the far-too-common belief that no-one's after you because you're not interesting enough. IPv4 is smaller than we think. It is not difficult to scan the entire ipv4 space in minutes. And every single one of those is going to knock your door on the way past.

I'm not sure about the article, but the blazingly-fast IP scanner sounds a lot like Masscan. It can scan the entire Internet in 5 minutes and has received a lot of press: https://github.com/robertdavidgraham/masscan . https://rushter.com/blog/how-masscan-works/ is one of many articles about it.

Here's an except from the masscan docs: