Anti-viruses today, are increasingly becoming more and more resource hungry. Gone are the days when you could keep one on your machine while doing your daily computations. Without a multi-core processor you are doomed to even attempt to multi-task with your applications when a scan is in progress. Not all of us can keep up with the constant hardware upgrades that each new version of these softwares require.
This is why I have said NO to memory resident anti-viruses. You can easily go on without them by following some basic precautions. Let us look at the most common ways that viruses infect a computer.
Downloaded Applications from the Internet
Such problems never occur if the source of the application is a trusted company such as Microsoft, Yahoo, Download.com, Softpedia, etc. If you don’t fully trust a brand or if its new to you, do some googling with the keyword virus along with the name of the company or the concerned product. It is very likely that if somebody has had problems with any such softwares, they would have reported it somewhere on the Internet and it is our responsibility to do the same and keep the net safe.
A greater issue with internet downloads is the widespread use of pirated softwares. Cracked/Patched editions of the softwares may allow users to use them unrestricted. But, they are also bloated with Trojans and viruses that steal away your sensitive information.
Removable Media
Applications in removable media such as Pen Drives & CD/DVD ROMs spread the viruses when they are shared among computers. The infection only occurs when an infected file is executed on the machine. Never execute doubtful applications received in untrustworthy or custom burned discs. Remember, viruses these days are silent and have no real visible interfaces. They run in the background logging your key-strokes and monitoring your activities. Thereafter, the information is sent to the hackers’ website.
Not executing applications alone will not solve the problem. Many viruses use the Autorun feature in Windows to automatically execute the application when the disc is inserted. Disabling Autorun in Windows XP is a solution to this problem. Vista’s User Access Control (UAC) lets you choose whether to execute an Autorun program residing in a disc.
Sharing USB Drives
Pen Drive viruses spread by replicating themselves onto drives as soon as they are plugged into the port on an infected PC. The infection consists of two files – the infected application (EXE file) and an Autorun.inf file which automatically executes the infected application on a system when the Pen Drive is jacked in.
Because the file system in Pen Drives resembles that of a Hard Disk Drive, the write operations are trivial for the lightweight viruses. This vulnerability does not exist on CD/DVD ROMs because burning to discs is a much more complex job.
Worms in Network
Worms are one of the most dangerous kinds of viruses. They exploit the security vulnerabilities in Operating Systems to spread without notice across the network(s). Whenever a new worm with the ability to exploit such vulnerabilities is released, thousands of computers get infected and turned into zombie machines. Its imperative to install a good Firewall if your computer is connected to the Internet.
Popups in Sites
Ironically, many viruses are spread via popups in Web Pages that claim to have found virus infections on your systems. New users unaware of this, install their so called “Solutions” and let them into their system. NEVER, and I mean NEVER install such applications. No web page can scan and detect Viruses & Spywares on your system, unless off course supported by a browser Add-On which installs a scanner on the system and that too with your permission.
These are only a few but common methods viruses spread by. The average user can easily protect himself from these by exercising his experience. Without a heavy Antivirus the performance & responsiveness of the system is very satisfying, more so if you are a heavy multi-tasker. All having said & done, it is wise to install an Antivirus once in a while and do a full system scan, after which the program can be de-installed.