Comprehensive guide on how to secure your Wireless network

October 20, 2006

The age of wireless computing has brought unprecedented freedom and mobility for computer systems users in a variety of circumstances. These days wireless networking products are so ubiquitous and inexpensive that just about anyone can set up a WLAN in a matter of minutes with less than $100 worth of equipment. This widespread use of wireless networks means that there may be dozens of potential network intruders lurking within range of your home or college dorm or office WLAN.        

The risks

Wireless networks don’t stop at the walls of your home. In fact, wireless networks often extend more than 300 feet from your wireless router. If you live in an apartment, dorm, or condominium, you may have dozens of neighbors who can access your wireless network. If you live in a house, your neighbors and even people on the street may be able to connect to your network.

It’s one thing to let a neighbor borrow your lawn mower, but you should think twice about allowing anyone to access your home network. There are several good reasons for this. People who can connect to your wireless network might be able to:

a. Slow down your Internet performance

b. View files on your computers and spread dangerous software

c. Monitor the Web sites you visit, read your e-mail and instant messages as they travel across the network, and copy your usernames and passwords

d. Send spam or perform illegal activities with your Internet connection

By setting up security features on your wireless network, you can make it very difficult for uninvited guests to connect.

Wireless networks are becoming increasingly popular, but they introduce additional security risks. If you have a wireless network, make sure to take appropriate precautions to protect your information.

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Complete guide to Wi-Fi Security at Hot-Spots

October 20, 2006

Wi-Fi hotspots have become ubiquitous at cafes, airports, restaurants, and other public location. In fact, more and more cities are creating hotspots that blanket entire metropolitan areas. Many municipalities have joined with local community groups to help grow the free wireless network by contributing volunteer time, knowledge, and donations..

.Wi-Fi hotspots present a unique challenge with respect to security especially because of the unknown computers sharing the same local network with you. Unlike your network at home or dorms or office networks, public hotspots whether at cafe centers or hotels usually broadcast their SSID’s, more often than not lack WEP or WPA encryption and definitely do not implement any kind of MAC filtering. After all, turning on any of these functions would negate the “public” aspect of hotspots.

That said, even if these public hotspots used closed networks and enabled encryption on their networks, making their customers go through hoops to get connected, there would still be no way to tell a “legitimate” client from a “malicious” one out to hack other customers’ data. Anyone with a credit card can sign up for hotspot service. So what can you do to protect yourself at a public hotspot? Plenty…

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How to setup ssh to tunnel VNC traffic throught the Internet

October 20, 2006

Virtual Networking Computing (VNC) is remote control software which allows you to view and interact with one computer using a simple program (viewer) on another computer (server) over a local area network or anywhere on the Internet. VNC is a cross-platform application that does not require the two computers to be the running the same operating system. For example you can use VNC to view your office Linux machine on your Windows PC at home. VNC is freely and publicly available and is distributed under the GNU General Public License (GPL). There are various distributions of VNC but the one we will be covering is RealVNC. VNC has two parts, a client and a server. The server is the program on the machine that shares its screen, and the client (or viewer) is the program that watches and interacts with the server. VNC software requires a TCP/IP connection between the server and the viewer. This is the standard networking protocol on LANs, WANs, broadband and dialup connections. Each computer has a unique IP address and may also have a name in the DNS. You will need to know the IP address or name of the server when you connect a viewer to it. If you are assigned a dynamic IP address, you might benefit from using a third party DNS management service.

Installing an SSH Server on Windows

Local port forwarding requires an SSH server running on the Windows machine. OpenSSH is provided as part of Cygwin which is an environment similar to Linux for Windows. Cygwin provides an install and update utility (setup.exe) to retrieve packages from the Internet. When you install Cygwin, select the OpenSSH package (available in the Net category). Once installed, complete the Cygwin configuration as shown below…

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How to develop ShellCode, a crucial point of any exploit software

October 20, 2006

It’s not an easy task to find a vulnerable service and find an exploit for it. It’s also not easy to defend against users who might want to exploit your system, if you are a system administrator. However, writing an exploit by yourself, to convert a news line from bug tracker into a working lockpick, is much more difficult. This article is not a guide on writing exploits, nor an overview of popular vulnerabilities. This is a step-by-step guide on developing a shellcode, a crucial point of any exploit software. Hopefully, learning how they work will help conscientious and respectable developers and system administrators to understand how malefactors think and to defend their systems against them.
How an Exploit Works

Take any exploit downloaded from the internet that promises you an easy root shell on a remote machine, and examine its source code. Find the most unintelligible piece of the code; it will be there, for sure. Most probably, you will find a several lines of strange and unrelated symbols; something like this:

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How to detect a Rootkit on your machine

October 20, 2006

A root kit is a collection of programs that intruders often install after they have compromised the root account of a system.
These programs will help the intruders clean up their tracks, as well as provide access back into the system.
Root kits will sometimes leave processes running so that the intruder can come back easily and without the system administrator’s knowledge.

Solution

chkrootkit V. 0.46a

Nelson Murilo [nelson@pangeia.com.br] (main author)
Klaus Steding-Jessen [jessen@cert.br] (co-author)

This program locally checks for signs of a rootkit.
chkrootkit is available at: http://www.chkrootkit.org/

This tool includes software developed by the DFN-CERT, Univ. of Hamburg (chklastlog and chkwtmp), and small portions of ifconfig developed by Fred N. van Kempen, [waltje@uwalt.nl.mugnet.org].

What’s chkrootkit?

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How to hide your email address from spammers, a thorough guide

October 20, 2006

Every IT professional worth his/her salt has their own webpage/blog these days. While you may have people from all over the globe dropping a line at your site, Email harvesters are the most unwanted visitors on any website. These email spambots crawl the web via search engines to find and extract email addresses from webpages. E-mail addresses in your blog or webpage are no secret to spam robots. Here’s a guide that should help you protect your email addresses from these spam spiders. Techniques mentioned use text manipulation, Masking, HTML, Flash, CSS, and JS to hide email addresses.
How email spammers operate? Email addresses always contain an @ symbol. Most spambots do a pattern-search for likely combinations of letters (abc@xyz.com) like billgates@microsoft.com or larrypage@google.org in the HTML source of webpages. Often they just search for the @ character and grab all the letters on each side on the assumption that it’s a valid email address.
How to keep your email address available to humans but invisible to email spiders? There are tons of Email Address Protector software that claim to protect your email address in web pages and get rid of junk mail - Don’t waste your money, they only encode your email or generate a javascript snippet. We will discuss manual email encoding techniques here. If a visitor clicks an encryped email link on your website, it will work as normal, but spam robots will not be able to extract the address from the link.

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How to opt out of ‘pre screened’ credit card and insurance offers

October 20, 2006

How many of you have grown tired and frustrated of those “pre screened” or “pre approved” credit card or insurance offers coming in your mail every day? Here is where an official site called OptOutPreScreen comes in.     

OptOutPrescreen is the official Consumer Credit Reporting Industry website to accept and process requests from customers to Opt-In or Opt-Out of firm offers of credit or insurance.Under the Fair Credit Reporting Act (FCRA), the Consumer Credit Reporting Companies, are permitted to include your name on lists used by creditors or insurers to make firm offers of credit or insurance. The FCRA also provides you the right to “Opt-Out”, which prevents Consumer Credit Reporting Companies from providing your credit file information for firm offers of credit or insurance that are not initiated by you.

 
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