With the wide spread use of internet, networks and computers have become increasingly susceptible to threats. These threats destroy data as well the programs that computers use. The objective of these threats is to destroy the data and to steal the vital information stored in computers.
This information is used by the attackers for their benefit. We occasionally hear about the data theft from credit card companies or banks, which lead to major financial losses. Also sometimes individual users are fooled in to giving their personal and sensitive information such as passwords or bank data leading to financial loss.
A computer virus is a program usually hidden within another simple program. It produces copies of itself and inserts them into other programs or files, in turn destroying the data and performing other malicious actions. Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread does not remain directly under our control. While developing the viruses, programmers have specific target in mind such as data theft or destruction of software, which runs the computers. The virus can be transferred hidden in files, programs or even in disks. The viruses can be of different kind but a common virus is macro virus.
A simple macro is series of programming steps that are stored in a single location. Macro allows automation of many actions with only a single keystroke. These can be embedded in the program files. Many programs, such as Word and Excel allow you to record a series of keystrokes and menu selections and then save them to a file. This helps eliminate doing the same action several times increasing efficiency. Macro viruses created with the intention of fooling the user can deceive them in sharing confidential information. This information can be used by the Macro to damage the computer data or software. The virus using macro files are most popular as they are:
Macro viruses can corrupt data, create new files, move text, flash colors, insert pictures, send files across the Internet, and format hard drives. Macro viruses are increasingly used as transport mechanisms to drop off even nastier bugs. Macro viruses modify registries, forward copies of it through emails, look for passwords, copy documents, and infect other programs. Macro viruses can do a lot of different damage in a lot of different ways. Example of macro Virus is Wazzo, W97M, etc.
Worms are very similar to viruses in the manner that they are computer programs that replicate copies of themselves (usually to other computer systems via network connections). Viruses often, but not always, contain some functionality that will interfere with the normal use of a computer or a program. Unlike viruses, however, worms exist as separate entities; they do not attach themselves to other files or programs. Because of their similarity to viruses, worms are also often referred to as viruses. Some examples of the worst Worms that impacted the web are:
1. Jerusalem is one of the earliest worms that spread in 1987. It is also one of the most commonly known viruses. It used to delete files that were executed on each Friday the 13th. It was first detected in the city of Jerusalem.
2. In 1991, thousands of machines running MS-DOS were hit by a new worm, Michelangelo. The virus would overwrite the hard disk or change the master boot record of infected hosts.
3. In 2007 Storm Worm hit the computers. Once hit, your machine becomes part of a large botnet which performs automated tasks that range from gathering data on the host machine, to sending infected emails to others. About 1.2 billion emails were sent from the infected computers propagating infection.
Since Worms spread mostly through the email attachments, the best ways to avoid them is using caution in opening emails. If the email is from an unidentified source, it is always best to delete it. Most of the time worms attach themselves to email. Even the sender of email does not recognize what they have forwarded, as emails are sent automatically using all contact information in the user’s profile.
A Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses into the system. Since they look like sincere programs they are referred as Trojan like the Trojan horse of Greek mythology. The Trojan program does not attach itself to the files like a virus nor replicate itself like a worm but it does provide unauthorized access to user’s computer.
They are mostly spread through internet downloads and online gaming programs. They mostly affect the targeted computers. The trojan program prompts you to do the normal functions such as inputting your email address or profile name. You do so, not knowing that, you have provided access to the malicious software. This software is capable of taking over the functionality of your computer. An infected computer will begin to operate slowly and will exhibit pop-ups from time to time. Eventually the computer will cease to operate, or crash.
The best way to avoid the Trojans is to adopt safe download practices. If you are not sure of the website safety, then it is probably best not to download any program from that source.
An example of the Trojan horse was “I love you” which infected several computers in USA and Asia, completely damaging the data of millions of computers.
A Spyware, as the name suggest, is a program used to spy on the computer system. This program will try to get all the confidential and sensitive information such as your bank account numbers, passwords, etc. Then this confidential data is misused to access user’s accounts. Spyware can also change the configuration of your computer, generally without obtaining your consent first.
There are a number of ways Spyware or other unwanted software can get on to computer. A common trick is to covertly install the software during the installation of other software that is being downloaded such as music or video or a file-sharing program. Once installed, the Spyware monitors user activity on the Internet and transmits that information in the background to someone else. Spyware can also gather information about e-mail addresses and even passwords and credit card numbers.
SpyWare sends information back to the spy ware’s home base via the user’s Internet connection, thus it eats user’s internet bandwidth. SpyWare applications running in the background can lead to system crashes or general system instability as they use memory and system resources of the user’s computer. SpyWare have the ability to monitor keystrokes, scan files on the hard drive, snoop other applications, such as chat programs or word processors. It also installs other SpyWare programs, read cookies, change the default home page on the Web browser. While doing so, it consistently relays this information back to the SpyWare author who will either sell the information to another party or use it for advertising or marketing purposes.
Some of the common Spywares are CoolWebSearch, Internet optimizer and Zango.
Malware is short for malicious software. Malware is any kind of unwanted software that is installed without your adequate consent. The intent of the malware is to damage the data or functionality of the computer or network. In fact all the threats mentioned above such as virus, Trojans, etc are examples of Malware.
The term “spam” refers to unsolicited commercial email (UCE) or unsolicited bulk email (UBE). It is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it. It is also referred as junk email. Unsolicited email mostly contains advertisements for services or products. However most of the spams are from marketers or user who are trying to deceive the users. The most commonly seen spam includes the following:
Spam emails is not only unwanted, it clogs your email accounts and uses unnecessary server space. This creates burden on servers in the businesses. Since Internet is a public platform, it is never possible to completely stop the Spam email. However precaution can be taken while looking at an unknown email addresses. Most of the email hosts can identify such users and help filter them.
Spam costs the sender very little to send. Most of the costs are paid for by the recipient or the carriers rather than by the sender. It is because of these additional costs that most of the hosts are very keen that users use spam filters as well as report spams so they can be stopped.
Hackers and crackers are the software programmers who use dubious ways to get control over your computer and systems. The intent of both hackers and crackers is to gain control over your computer so that they can get the sensitive confidential information. They then use this information against you by stealing money, personal data, pictures, bank details and government military information, so on and so forth.
This information can either be sold for money or hackers access account themselves to rob you directly. Originally hackers were the gifted programmers who gain access to the systems or network to show case the security loopholes to the administrators. Later the term cracker was coined for such activist who had intentions of doing malicious activities. Crackers have an end goal of destroying data and network for personal monetary gains.
Anti Virus tools are the software programs that help detect the virus in emails or files and hence protect our computers. These tools can detect virus, worms, Trojans as well as spyware and adware. They block us from visiting unsafe websites, and also downloading unsafe programs from such websites. They protect us from identity thefts and threats from phishing websites. There are several commercial antivirus software available such as Norton, Mcafee, K7, Quickheal, etc.
There are threats to the computers that are sometimes hard to avoid. Unknowingly we may open an email that may have virus attachments and can destroy all the program and data on our computer. That is why to protect ourselves from such unknown threat; we need to assure backing up the data. The basic principal on data back up is very simple, just make another copy of the data and keep it elsewhere than on the same computer. This guarantees that once the data on your computer gets corrupted due to a threat, you can reload the data again on your computer once it has been rectified.
These days you have external hard drives which can back up data. Also most of the smart devices are also used to back up the data.