What do I do about hacker attacks?

I have a Windows Server 2008 setup behind a firewall without any port forwards to the server. I do have an Untangle Internet Security Appliance with an OpenVPN connection setup for (2) remote users. The remote users run a 'RemoteApp' from the server but do not actually log onto the server with a Terminal Server session. I have installed monitoring software on the server. One of the daily checks is a 'Hacker' check, which has been reporting more than (100) unsuccessful login attempts within a (24) hour period. Should I be concerned about the failed logins? What should I do to stop the failed login attempts?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

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.

John MeggersNetwork ArchitectCommented:
Based on what you describe, it sounds like access to the server is only via the VPN, that there are no ports open on the FW allowing traffic to the server. If that's not the case, and there are ports open on the FW to allow access to the server, then it's entirely possible these are real attempts to access the server, in which case, you "authentication layer" appears to be working.   If that is the case, what are you seeing in the VPN logs?  I agree with you, I would be curious to understand where these unsuccessful logins are coming from.  Is it possible they're the result of some internal process trying to access the server?  

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
sahinmanAuthor Commented:
One of the laptops with VPN access to the network was infected with malware. I performed a format/reinstall and the hacker attacks have gone to zero!
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
Network Analysis

From novice to tech pro — start learning today.