if someone knows my IP address, what is the worst he can do

[brannsiu]

I don't normally turn off my PC and it's connected to the internet for 24 hours. I am not sure but I think my ISP provides me a static IP address that does not change usually.

If someone knows my IP address, and I don't have firewall installed now, I am running on Windows 7 and I do Windows Update from time to time. What is the worst thing he can do to my PC?

 

[ingtar33]

remote into your system.

 

[USAFRet]

I don't normally turn off my PC and it's connected to the internet for 24 hours. I am not sure but I think my ISP provides me a static IP address that does not change usually.

If someone knows my IP address, and I don't have firewall installed now, I am running on Windows 7 and I do Windows Update from time to time. What is the worst thing he can do to my PC?

Does this public IP address go to a router, or is your PC connected directly to the modem?

 

[techgeek]

The person could DDoS you which would interrupt you internet access.

 

[CaptainAustin]

First I would HIGHLY advise that you turn on the firewall on windows.

Also If a hacker had your IP address, he/she could launch a Distributed Denial of Service (DDoS) attack on it, and make the service unavailable for the intended users.
He/She could launch Brute Force SSH attacks and attempt to gain access to the machine.
He/She could also scan for the services running OR any open ports on the host and would try to exploit it in some manner. (any FTP, Mail, Mysql, VNC etc)
If the user and the hacker shares the same LAN, the hacker could target the user with Address Resolution Protocol spoofing and launch a Man in the Middle (communications attack) attack for all the internet communications.

 

[brannsiu]

to USAFRet
My PC connected through a router and then to the broadband modem

(In fact,it's not a modem, it's a lan port on the wall, but between the PC and the port there is a router through

 

[USAFRet]

to USAFRet
My PC connected through a router and then to the broadband modem

(In fact,it's not a modem, it's a lan port on the wall, but between the PC and the port there is a router through

Then all they can see is the router IP. Not your PC.
For instance, my PC is currently 192.168.1.18 (or similar). Nothing you can do with that, and the outside world does not see that.

The modem/router IP would be 102.97.xxx.xxx or something. The router has its own firewall.
At most, someone could attempt a DDOS. Or if really knowledgeable, and you are a specifically juicy target...possibly exploit the routers known issues.

Like if you turn on Remote administration, and you leave the username/password for the router at the default settings.
So, in theory, someone could log on to your router from elsewhere, and change the settings, see what machines are connected internally, etc.

However, you are not a juicy target.

 

[jsmithepa]

What USAret says.

Between your PC and the Internet there is a NAT device, and you know this because your PC has a private IP, typically 192.168.x.x. This NAT thingy is acting like a barrier, people outside cannot directly get to your PC, UNLESS you specifically configure stuff to allow so. This is what I call Frontal Attack.

But hackers these days don't need to do Frontal Attack, they do something much easier like Phisting. Entice you to click a dubious link and BAM! they have planted something on your PC.

So that's what you are dealing with. Having your PC on 24x7 it means if you are infected, then your PC will be a "BOT" (google for that term) for the bad guys.

Your ball.