Detect hack wifi at your home ?



Are you using a wifi at your home? You may not know this, however your harmless neighbour may be snopping and cracking your wifi key while using your Internet for free. Using your Internet is still considered harmless. Once an attacker is on your network, it is not so hard to use other methods to get your email accounts or Maybank2u account. Even your video sex chat may be compromised.

Wireless hacking is now more common than you know.You can buy gadgets at less than Rm 200 over the Internet to crack Wifi-key. My wireless network has been hacked into a few times in my life. My guess is most attack goes unnoticed since people do not know how to detect it at the first place.

 

Having 7 years experience in IT security,  I have pretty strong network key, using WPA2 and cleverly enough not broadcast my SSID. I had a shock yesterday when I saw a stranger PC in my network. I have a strong reason to believe that my neighbour has hacked into my network a few times event I’ve changed the key  to a stronger one.

 

How to check intrusion PC in your network ? 

1. Easiest way is to check from your wireless router.  This may vary from router manufacturer and model. Go to your router DHCP list. The method may not be so perfect, however this will give an idea who is connected to your network. Do a count of total PC, mobile devices or laptops that is up and running. If you see one or two extra IP Address and foreign hostname in your network, the chances are you have been hacked!

 

for this example there are 1 PC connected into the network

 

 

2. This method is a little more advance. However it does give a much clearer idea on IP Addresses that are on your network.

 

Download Nmap from the Internet. Run a Ping scan over your subnet. It will display IP address that are live on your network.

 

To run , Start->run

C:\>nmap -sP 192.168.1.0/24

Starting Nmap 5.51 ( http://nmap.org ) at 2012-02-24 15:15 Malay P
ard Time
Nmap scan report for 192.168.1.1
Host is up (0.018s latency).
MAC Address: 94:44:52:8E:2A:04 (Belkin International)
Nmap scan report for 192.168.1.99
Host is up (0.10s latency).
MAC Address: 00:18:DE:B9:27:64 (Intel)
Nmap scan report for 192.168.1.100
Host is up (0.10s latency).
MAC Address: 00:22:75:76:34:CD (Belkin International)
Nmap scan report for 192.168.1.101
Host is up.
Nmap done: 256 IP addresses (4 hosts up) scanned in 8.61 seconds

There are 4 IP addresses Up and running which includes the WiFi router from the Nmap command.

 

 

 

Ok, we have know how to detect the intrusive element on the network. The next step is possible to secure your network and prevent reintrusion again.

 

 Things you can do to make your network secure  ? 

 

 

For my case, things did not workout although the methods above are implemented. I can see the intrusive PC again a few hours later. The intruder seems to be pretty good at this. Cracking the key again. Fortunately my Belkin router comes with MAC address filtering option for the network. MAC address would be the hardware address on the network card. However this would mean that I will need to add all the connected device MAC address into the router table.

 

To collect MAC address , go to your PC Start->run

Type

Ipconfig /all

 

Wireless LAN adapter Wireless Network Connection:

Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Wireless G USB Adapter
Physical Address. . . . . . . . . : XX-XX-6D-E1-2F-02          <—- MAC address
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

 

 

After I added the MAC address filtering, the intruder does not shows up anymore. The funny thing is, one of my particular neighbor seems to hang out on the lawn more after I’ve implemented the security on my Wifi Network.

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Posted on February 24, 2012 at 3:46 pm by yuliang11 · Permalink
In: photography · Tagged with: , , , ,

2 Responses

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  1. Written by PPKia
    on August 2, 2012 at 6:08 pm
    Reply · Permalink

    you are so noob

    mac address can be cloned.
    wpa2 is also not secure.

    use lan cable instead.
    if you are so paranoid, dun use wifi.

    whoever is hacking your wifi is also an idito.
    wifi is free all over town, even McD has it.

    • Written by yuliang11
      on August 2, 2012 at 6:14 pm
      Reply · Permalink

      That’s one pea brained statement. Do you know how much it cost to LAN cable a whole office compared to wifi ? MAC can be cloned but how do you know what MAC is being allowed? don’t tell me you are going to brute force a MAC address and a 20 chararacter WPA2. Also it’s more convenient to use a neighbour’s wifi rather than to drive to MCD. next time use your brain that is stucked between your ass before you comment.

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