After looking back at this thread a ways, I feel like this isn't really the proper place for this anymore, but it is the best I could find without starting an unnecessary new one.
I am the closest thing to an IT guy at the little company I work at. Which means I fix printers, set up new computers, etc. We have a server with a domain that everyone connects to with individual PCs, and all network traffic goes through the server. That's literally about all I can tell you about it.
We've been getting some really insidious fake emails lately that look pretty legit, even having snippets of real conversations in them, but they are clearly from bogus addresses once you know to look for it. They have various attachments, zip files with passwords, excel files with macros, etc. Of course, several people opened the fucking things even though gmail blatantly said it looked suspicious. I'm doing scans on everything that I can, but I'm not sure if it is going to catch everything or even what the attachments had in them malware-wise.
I feel like our network is slower now. Could be placebo, could be a lot of things, but I want to make sure it isn't someone's computer sending out shitloads of packets. We had stuff like that in the mid-2000s and it was hard to pin down.
Is there a free tool that I can install on the server and have it list how much data is being and sent and received per machine or IP address or whatever? I say free because I don't even know if anything is actually wrong, and I'd rather not convince them to buy something that a) I have no idea how to properly use, and b) might not even be needed.
Thanks!