Internet Security: How to implement Hardware and Software Firewall

There are two kinds of firewalls: software and hardware firewalls. Although both provide similar benefits, a hardware firewall is more efficient and cost effective when you want to protect more than one computer. Firewalls are essential to implementing efficient Internet Security.

What is it?

A hardware firewall is a device that is placed between an Internet connection and a network. Computers connect to the Internet via the network. But all data coming in will first be checked by the firewall.  A firewall has the ability to check data entering into a computer through an Internet connection. If the source of the data is not reputable, the firewall will prevent it from being downloaded. A firewall also has the ability to identify and block inbound scans that hackers use to exploit security holes within a network. 

Using a Hardware Firewall for Internet Security

When setting up a hardware firewall, it is important that it is configured properly. If not properly configured, the firewall will block all types of connections or it may not work at all. A hardware firewall can be configured to block certain types of applications. A firewall is also useful in situations where a computer has already been infected with spyware. Since the firewall can prevent data from being sent into or out of the device, it will block the data being sent by the spyware application. Therefore, it can be used to prevent identity theft. 

How does a firewall work?

A firewall utilizes packet filtering to apply rules within a network. It maintains Internet Security by analyzing packets that are received and sent by the computer that it is protecting. If the packet contains any indications that it may be a threat, it is blocked.  A fairly recent upgrade in regards to firewall technology is known as SPI or Stateful Packet Inspection. SPI allows a firewall to check additional characteristics within a data packet. This feature allows firewalls to work more efficiently. 

How much does it cost?

Implementing Internet Security is not always cheap. However, a moderate investment can lead to an efficient security system. A hardware firewall for a home network system will cost around five thousand rupees. However, for enterprises, the cost will go up as more complex security features become necessary.  Buying a VPN service is another alternative recommended for personal users to secure online activities.

A firewall is considered to be the first line of defense of any efficient security system. Therefore, implementing it within a network is considered to be vital. 

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[How to] Run infected files without getting your system infected

Yes it’s true that you can run infected files on your system without getting the system infected. Sandboxie is an Application that allows you to do so. This is useful in circumstances where you have a USB device or installing a not so known file on your computer. Sandboxie can help you install the program even if it is infected without getting your system affected.

Here is a quick demonstration

I have downloaded a infected file. 

2. Kaspersky prompts me that the file is infected.


3. Thankfully I have Sandboxie on installed on my computer.

4. Now run the file. You have to navigate to the folder that has the file which is infected.

5. Right Click on the file and then Click “Run Sandboxed” from the drop down menu.

 

Link: Download Sandboxie

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How Computer Viruses Work

Strange as it may sound, the computer virus is something of an Information Age marvel. On one hand, viruses show us how vulnerable we are -- a properly engineered virus can have a devastating effect, disrupting productivity and doing billions of dollars in damages. On the other hand, they show us how sophisticated and interconnected human beings have become.

For example, experts estimate that the Mydoom worm infected approximately a quarter-million computers in a single day in January 2004. Back in March 1999, the Melissa virus was so powerful that it forced Microsoft and a number of other very large companies to completely turn off their e-mail systems until the virus could be contained. The ILOVEYOU virus in 2000 had a similarly devastating effect. In January 2007, a worm called Storm appeared -- by October, experts believed up to 50 million computers were infected. That's pretty impressive when you consider that many viruses are incredibly simple.
When you listen to the news, you hear about many different forms of electronic infection. The most common are:

• Viruses - A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
  
   
• E-mail viruses - An e-mail virus travels as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's e-mail address book. Some e-mail viruses don't even require a double-click -- they launch when you view the infected message in the preview pane of your e-mail software [source: Johnson].

• Trojan
  horses - A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.

• Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.
  
   

Virus Origins
Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.
Unlike a cell, a virus has no way to reproduce by itself. Instead, a biological virus must inject its DNA into a cell. The viral DNA then uses the cell's existing machinery to reproduce itself. In some cases, the cell fills with new viral particles until it bursts, releasing the virus. In other cases, the new virus particles bud off the cell one at a time, and the cell remains alive.

Patch Tuesday On the second Tuesday of every month, Microsoft releases a list of known vulnerabilities in the Windows operating system. The company issues patches for those security holes at the same time, which is why the day is known as "Patch Tuesday." Viruses written and launched on Patch Tuesday to hit unpatched systems are known as "zero-day" attacks. Thankfully, the major anti-virus vendors work with Microsoft to identify holes ahead of time, so if you keep your software up to date and patch your system promptly, you shouldn't have to worry about zero-day problems.

A computer virus shares some of these traits. A computer virus must piggyback on top of some other program or document in order to launch. Once it is running, it can infect other programs or documents. Obviously, the analogy between computer and biological viruses stretches things a bit, but there are enough similarities that the name sticks.
People write computer viruses. A person has to write the code, test it to make sure it spreads properly and then release it. A person also designs the virus's attack phase, whether it's a silly message or the destruction of a hard disk. Why do they do it?
There are at least three reasons. The first is the same psychology that drives vandals and arsonists. Why would someone want to break a window on someone's car, paint signs on buildings or burn down a beautiful forest? For some people, that seems to be a thrill. If that sort of person knows computer programming, then he or she may funnel energy into the creation of destructive viruses.
The second reason has to do with the thrill of watching things blow up. Some people have a fascination with things like explosions and car wrecks. When you were growing up, there might have been a kid in your neighborhood who learned how to make gunpowder. And that kid probably built bigger and bigger bombs until he either got bored or did some serious damage to himself. Creating a virus is a little like that -- it creates a bomb inside a computer, and the more computers that get infected the more "fun" the explosion.
The third reason involves bragging rights, or the thrill of doing it. Sort of like Mount Everest -- the mountain is there, so someone is compelled to climb it. If you are a certain type of programmer who sees a security hole that could be exploited, you might simply be compelled to exploit the hole yourself before someone else beats you to it.
Of course, most virus creators seem to miss the point that they cause real damage to real people with their creations. Destroying everything on a person's hard disk is real damage. Forcing a large company to waste thousands of hours cleaning up after a virus is real damage. Even a silly message is real damage because someone has to waste time getting rid of it. For this reason, the legal system is getting much harsher in punishing the people who create viruses.


Virus History
Traditional computer viruses were first widely seen in the late 1980s, and they came about because of several factors. The first factor was the spread of personal computers (PCs). Prior to the 1980s, home computers were nearly non-existent or they were toys. Real computers were rare, and they were locked away for use by "experts." During the 1980s, real computers started to spread to businesses and homes because of the popularity of the IBM PC (released in 1982) and the Apple Macintosh (released in 1984). By the late 1980s, PCs were widespread in businesses, homes and college campuses.
The second factor was the use of computer bulletin boards. People could dial up a bulletin board with a modem and download programs of all types. Games were extremely popular, and so were simple word processors, spreadsheets and other productivity software. Bulletin boards led to the precursor of the virus known as the Trojan horse. A Trojan horse is a program with a cool-sounding name and description. So you download it. When you run the program, however, it does something uncool like erasing your disk. You think you are getting a neat game, but it wipes out your system. Trojan horses only hit a small number of people because they are quickly discovered, the infected programs are removed and word of the danger spreads among users.

Floppy disks were factors in the spread of computer viruses.

The third factor that led to the creation of viruses was the floppy disk. In the 1980s, programs were small, and you could fit the entire operating system, a few programs and some documents onto a floppy disk or two. Many computers did not have hard disks, so when you turned on your machine it would load the operating system and everything else from the floppy disk. Virus authors took advantage of this to create the first self-replicating programs.

Early viruses were pieces of code attached to a common program like a popular game or a popular word processor. A person might download an infected game from a bulletin board and run it. A virus like this is a small piece of code embedded in a larger, legitimate program. When the user runs the legitimate program, the virus loads itself into memory and looks around to see if it can find any other programs on the disk. If it can find one, it modifies the program to add the virus's code into the program. Then the virus launches the "real program." The user really has no way to know that the virus ever ran. Unfortunately, the virus has now reproduced itself, so two programs are infected. The next time the user launches either of those programs, they infect other programs, and the cycle continues.
If one of the infected programs is given to another person on a floppy disk, or if it is uploaded to a bulletin board, then other programs get infected. This is how the virus spreads.
The spreading part is the infection phase of the virus. Viruses wouldn't be so violently despised if all they did was replicate themselves. Most viruses also have a destructive attack phase where they do damage. Some sort of trigger will activate the attack phase, and the virus will then do something -- anything from printing a silly message on the screen to erasing all of your data. The trigger might be a specific date, the number of times the virus has been replicated or something similar.


Virus Evolution

Other Threats Viruses and worms get a lot of publicity, but they aren't the only threats to your computer's health. Malware is just another name for software that has an evil intent. Here are some common types of malware and what they might do to your infected computer: Adware puts ads up on your screen. Spyware collects personal information about you, like your passwords or other information you type into your computer. Hijackers turn your machine into a zombie computer. Dialers force your computer to make phone calls. For example, one might call toll 900-numbers and run up your phone bill, while boosting revenue for the owners of the 900-numbers. [source: Baratz and McLaughlin]

As virus creators became more sophisticated, they learned new tricks. One important trick was the ability to load viruses into memory so they could keep running in the background as long as the computer remained on. This gave viruses a much more effective way to replicate themselves. Another trick was the ability to infect the boot sector on floppy disks and hard disks. The boot sector is a small program that is the first part of the operating system that the computer loads. It contains a tiny program that tells the computer how to load the rest of the operating system. By putting its code in the boot sector, a virus can guarantee it is executed. It can load itself into memory immediately and run whenever the computer is on. Boot sector viruses can infect the boot sector of any floppy disk inserted in the machine, and on college campuses, where lots of people share machines, they could spread like wildfire.
In general, neither executable nor boot sector viruses are very threatening any longer. The first reason for the decline has been the huge size of today's programs. Nearly every program you buy today comes on a compact disc. Compact discs (CDs) cannot be modified, and that makes viral infection of a CD unlikely, unless the manufacturer permits a virus to be burned onto the CD during production. The programs are so big that the only easy way to move them around is to buy the CD. People certainly can't carry applications around on floppy disks like they did in the 1980s, when floppies full of programs were traded like baseball cards. Boot sector viruses have also declined because operating systems now protect the boot sector.
Infection from boot sector viruses and executable viruses is still possible. Even so, it is a lot harder, and these viruses don't spread nearly as quickly as they once did. Call it "shrinking habitat," if you want to use a biological analogy. The environment of floppy disks, small programs and weak operating systems made these viruses possible in the 1980s, but that environmental niche has been largely eliminated by huge executables, unchangeable CDs and better operating system safeguards.


E-mail Viruses
Virus authors adapted to the changing computing environment by creating the e-mail virus. For example, the Melissa virus in March 1999 was spectacular. Melissa spread in Microsoft Word documents sent via e-mail, and it worked like this:

Phishing and Social Engineering While you may be taking steps to protect your computer from becoming infected by a virus, you may very well run into another, more insidious type of attack. Phishing and other social engineering attacks have been on the rise. Social engineering is a fancy term for someone trying to get you to give up your personal information -- online or in person -- so they can use it to steal from you. Anti-spam traps may catch e-mail messages coming from phishers, but the U.S. Computer Emergency Readiness Team says the best way for you to beat them at their own game is to be wary. And never give out your personal or financial information online.

Someone created the virus as a Word document and uploaded it to an Internet newsgroup. Anyone who downloaded the document and opened it would trigger the virus. The virus would then send the document (and therefore itself) in an e-mail message to the first 50 people in the person's address book. The e-mail message contained a friendly note that included the person's name, so the recipient would open the document, thinking it was harmless. The virus would then create 50 new messages from the recipient's machine. At that rate, the Melissa virus quickly became the fastest-spreading virus anyone had seen at the time. As mentioned earlier, it forced a number of large companies to shut down their e-mail systems.
The ILOVEYOU virus, which appeared on May 4, 2000, was even simpler. It contained a piece of code as an attachment. People who double-clicked on the attachment launched the code. It then sent copies of itself to everyone in the victim's address book and started corrupting files on the victim's machine. This is as simple as a virus can get. It is really more of a Trojan horse distributed by e-mail than it is a virus.
The Melissa virus took advantage of the programming language built into Microsoft Word called VBA, or Visual Basic for Applications. It is a complete programming language and it can be programmed to do things like modify files and send e-mail messages. It also has a useful but dangerous auto-execute feature. A programmer can insert a program into a document that runs instantly whenever the document is opened. This is how the Melissa virus was programmed. Anyone who opened a document infected with Melissa would immediately activate the virus. It would send the 50 e-mails, and then infect a central file called NORMAL.DOT so that any file saved later would also contain the virus. It created a huge mess.
Microsoft applications have a feature called Macro Virus Protection built into them to prevent this sort of virus. With Macro Virus Protection turned on (the default option is ON), the auto-execute feature is disabled. So when a document tries to auto-execute viral code, a dialog pops up warning the user. Unfortunately, many people don't know what macros or macro viruses are, and when they see the dialog they ignore it, so the virus runs anyway. Many other people turn off the protection mechanism. So the Melissa virus spread despite the safeguards in place to prevent it.
In the case of the ILOVEYOU virus, the whole thing was human-powered. If a person double-clicked on the program that came as an attachment, then the program ran and did its thing. What fueled this virus was the human willingness to double-click on the executable.
Worms
A worm is a computer program that has the ability to copy itself from machine to machine. Worms use up computer time and network bandwidth when they replicate, and often carry payloads that do considerable damage. A worm called Code Red made huge headlines in 2001. Experts predicted that this worm could clog the Internet so effectively that things would completely grind to a halt.
A worm usually exploits some sort of security hole in a piece of software or the operating system. For example, the Slammer worm (which caused mayhem in January 2003) exploited a hole in Microsoft's SQL server. "Wired" magazine took a fascinating look inside Slammer's tiny (376 byte) program.
Worms normally move around and infect other machines through computer networks. Using a network, a worm can expand from a single copy incredibly quickly. The Code Red worm replicated itself more than 250,000 times in approximately nine hours on July 19, 2001 [Source: Rhodes].
The Code Red worm slowed down Internet traffic when it began to replicate itself, but not nearly as badly as predicted. Each copy of the worm scanned the Internet for Windows NT or Windows 2000 servers that did not have the Microsoft security patch installed. Each time it found an unsecured server, the worm copied itself to that server. The new copy then scanned for other servers to infect. Depending on the number of unsecured servers, a worm could conceivably create hundreds of thousands of copies.
The Code Red worm had instructions to do three things:

• Replicate itself for the first 20 days of each month
• Replace Web pages on infected servers with a page featuring the message "Hacked by Chinese"
• Launch a concerted attack on the White House Web site in an attempt to overwhelm it [Source: eEye Digital Security]

Upon successful infection, Code Red would wait for the appointed hour and connect to the www.whitehouse.gov domain. This attack would consist of the infected systems simultaneously sending 100 connections to port 80 of www.whitehouse.gov (198.137.240.91).
The U.S. government changed the IP address of www.whitehouse.gov to circumvent that particular threat from the worm and issued a general warning about the worm, advising users of Windows NT or Windows 2000 Web servers to make sure they installed the security patch. .

Reported Viruses According to a report by Symantec published in September 2007, the company received more than 212,000 reports of viruses, worms and other threats during the first half of 2007, a 185% increase over the second half of 2006.

A worm called Storm, which showed up in 2007, immediately started making a name for itself. Storm uses social engineering techniques to trick users into loading the worm on their computers. So far, it's working -- experts believe between one million and 50 million computers have been infected [source: Schneier].
When the worm is launched, it opens a back door into the computer, adds the infected machine to a botnet and installs code that hides itself. The botnets are small peer-to-peer groups rather than a larger, more easily identified network. Experts think the people controlling Storm rent out their micro-botnets to deliver spam or adware, or for denial-of-service attacks on Web sites.

 

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How to Remove a Computer Virus

If your computer has been hit with a virus, don't give up. There's still hope!
We all know malware is out there. Malware includes applications that spy on you, corrupt your data, destroy your hard drive or give control of your machine to someone thousands of miles away. No matter what form it takes, it's bad business. And since there are a lot of examples of malware in the wild, it may only be a matter of time before you become the victim of a malware attack.
The most important advice we can give anyone who believes he or she has a computer with malware on it is this: Don't panic. Also, don't assume that you need to wipe your computer clean and start from scratch. Often you can remove malware without having to erase everything else. You may lose some data in the process, but you probably won't lose everything.
First you need to determine if your computer has a virus at all. You might suspect your computer of having a virus if it seems to be sluggish. If your Web browser suddenly looks different or automatically goes to a site you don't recognize, that's a good indication that you've got some malware. If your computer is unstable and crashes fairly often, you may have a problem. And if you try to access files but receive a message saying they're corrupted, that's another sign.
If you do think your computer has a virus, you need to run antivirus software to weed it out. Some viruses disable antivirus software -- they're clever that way. If you don't have any antivirus software, now's a good time to purchase or download an application. A few malware variants will try to block you from downloading antivirus software. If that's the case, you may need to download the software on another computer and transfer it to disk or a flash drive.

 

Detecting and Removing a Computer Virus

Antivirus software is practically a requirement for anyone using the Windows operating system. While it's true you can avoid computer viruses if you practice safe habits, the truth is that the people who write computer viruses are always looking for new ways to infect machines. There are several different antivirus programs on the market -- some are free and some you have to purchase. Keep in mind that free versions often lack some of the nicer features you'll find in commercial products.

Two's a Crowd

If one antivirus program is good, two is better, right? Wrong. Antivirus software tends to use up a large percentage of your computer's processing power. Running more than one antivirus program will slow your computer to a crawl and possibly cause it to crash. And not all antivirus programs are compatible with one another, which can make your computer even more unstable.

Let's start with the assumption that you're able to run antivirus software -- we'll look into what to do if this isn't the case a little later. Assuming your antivirus software is up to date, it should detect malware on your machine. Most antivirus programs have an alert page that will list each and every virus or other piece of malware it finds. You should write down the names of each malware application your software discovers.
Many antivirus programs will attempt to remove or isolate malware for you. You may have to select an option and confirm that you want the antivirus software to tackle the malware. For most users, this is the best option -- it can be tricky removing malware on your own.
If the antivirus software says it has removed the malware successfully, you should shut down your computer, reboot and run the antivirus software again. This time, if the software comes back with a clean sweep, you're good to go. If the antivirus software finds different malware, you may need to repeat the previous steps. If it finds the same malware as before, you might have to try something else.


Advanced Computer Virus Removal Tips



  Give Viruses the Boot (Disk)

Some antivirus software will let you create a special boot disk. After creating a boot disk, you should reboot your computer with the disk in the drive. Your computer will read from the disk and load a limited OS and run a virus scan. With luck, this method will allow you to bypass the malware's code and disable it.

If you can't access your antivirus software or you keep seeing the same malware pop up scan after scan, you may need to try and start your computer in Safe Mode. Many computer viruses will store files in your Windows registry folder. This folder acts like a database of instructions and tells your operating system important information about the programs you have on your computer. It can also tell viruses to activate as soon as the operating system loads. Starting your computer in Safe mode allows you to work with your machine using only the core elements of the Windows OS.

Try running your antivirus software in this mode. If you see new malware pop up, you may have hit upon your solution. Some malware exists only to download other kinds of malware and install them on your machine. If you can remove all of these applications, you'll be in good shape.

If for some reason your antivirus software can't remove the virus on its own, it's time to do a little more research. Remember when we said you should write down the names of all the malware applications that your software discovered? Here's where that comes into play. You'll need to research each of those files online using the appropriate Internet security firm. Make sure to use the same firm that produces the antivirus software you're using. That's because different firms sometimes give the same virus different names. Not all firms will refer to the same virus the same way.

Most Internet security firms will list all the files associated with a particular virus and tell you where you can expect to find those files. You may have to do some digging to find each file. Before you delete any files, you should save a backup copy of your Registry folder. If you accidentally delete the wrong file, you may make it difficult or impossible to run your computer properly.

Delete all the files associated with the malware on your list. Once that's done, you'll need to reboot your computer and run your antivirus software again. Hopefully nothing else will pop up.

You may want to update your login information for your various accounts online. Some malware has keylogging software that can send your passwords and information to a remote user. It's better to be safe than sorry.




Computer Virus Protection

Worst-case Scenario

There are some simple rules you can follow that will help you avoid computer viruses. Most of these fall under the category of common sense.


Don't open strange e-mail attachments or click on hyperlinks in e-mail. Virus programmers love to trick people into clicking on links that will lead them to malicious software. Let people know that you don't click on hyperlinks in e-mail unless the sender includes a description of the link and what it leads to. If your e-mail client supports autolaunch, turn it off. Otherwise you might automatically activate a computer virus just by opening the e-mail.


The same applies to other messages you might encounter. Hyperlinks in message boards, Facebook messages or instant messages can sometimes lead to malware. Pay attention to the source of the message. Look for any unusual signs like misspellings or odd sentence structure, particularly if the person who sent you the message normally avoids errors. If you do see an odd link, you may want to let the sender know -- he or she might be the victim of a hacked account.


Don't visit questionable Web sites. This includes everything from software, music and video piracy sites to porn pages. Many current Web browsers will alert you if you try to go to a site that is known for hosting malware. Pay attention to these warnings and stay away from those sites.

Pay close attention to any windows that pop up while you surf the Web. If you see a notification claiming that you need to download the latest video driver to watch something, use caution. This is a common tactic used to distribute malware.


Run your antivirus software at least once a week. You should also make sure your antivirus software and OS remain current by downloading updates and patches on a regular basis. Most antivirus software updates at least once a week as security firms add more virus information to their databases.

Avoiding viruses might sound like a lot of work but keep in mind it's easier than fixing a computer that's been hit with a virus. Learn more about computer viruses and safe computing on the next page.

If you can't seem to delete the viruses no matter which method you try, it may be time to bite the bullet and perform a complete system wipe. This involves formatting your hard drive and reloading the operating system. This will delete all of your information -- be sure to save backups of any important, virus-free files before you start.

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