Port scanning: what would cause it from a PC?

A client is being blocked about once a week from our (LAMP, Cpanel, with IFD firewall) server because of Port Scanning.

What in a PC would cause port scanning from his home isp connection, and how to curtail?

thanks!
willsherwoodAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

kevin_uCommented:
If it is really port scanning, its a virus, trojan and the computer may be part of a botnet.  If that PC and/or that user has access to any sensitive information, I'd deny access until it is cleared up.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Steve JenningsIT ManagerCommented:
"What in a PC would cause port scanning from his home isp connection, and how to curtail?"

A user with a little bit of knowledge playing with a tool downloaded from the internet that he really doesn't understand.

I agree with kevin u . . . block him until that nonsense stops.

Good luck,
SteveJ
0
willsherwoodAuthor Commented:
the client's PC is idle overnight, he has anti-virus.
doesn anything that's non malicious do port scanning?
0
Steve JenningsIT ManagerCommented:
That depends: if the range is very small . . . sure some apps will try to connect over a small range of ports because they are somewhat firewall savvy and as you say their intention is non-malicious. However, as the range of ports gets larger, it begins to be a stretch to call them non-malicious regardless of their intent because of the consequence.

What is the range of ports being scanned?

Good luck,
SteveJ
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Networking

From novice to tech pro — start learning today.