A computer virus spreads from one system to another and causes various kinds of harm, including data deletion or corruption, spreading to other computers through email, and deleting or locking the hard disk. Attachments that come along with the email messages are the most common way through which computer viruses are spread. They also spread through downloads from some websites, they are also found in the pirated software. Some of the common kinds of computer viruses are as follows:

Worms
This kind of virus does not require user interaction to spread itself. Emails with suspicious attachments often have these worms.

Trojan horse
A Trojan horse may enter your PC while being attached to a legitimate program. Such programs do not spread by themselves but use worms, viruses, and downloaded software to infect other computers.

Spyware
Spyware will track your computer activities. It may collect personal, financial, and other information stored on the PC and its hard disk, and on the cloud as well.

Rogue security software
Such programs give you the appearance that the computer is infected by some virus, and they want you to download a file for removing it.

Virus scan
A virus scan is conducted by a virus scanner, which can be termed as a kind of antivirus software program.

How virus scans work
The scanning method used by the scanner can be automatic, manual, or hybrid. The scanner also operates by synergizing in conjunction with other elements of an antivirus software, e.g., the virus containers.

Updated database
The new anti-virus protection software possess the icon or window interface. Many virus scanners can still have the command line type interface. The scanners individually examine each file in the drive. They subsequently isolate the harmful viruses and malicious programs and then remove them completely from the hard drive of the PC. For doing this, the virus scanner relies on an updated virus database so that the scanner can identify the newest viruses as well.

Scan scheduling
Processes of virus scans may vary in its strength and comprehensiveness. While a short duration virus scan only looks into certain programs and applications more exposed to the threat of virus, the comprehensive virus scans checks almost all the system configurations to find out any virus signature virus or malware located or associated with the computer and its programs.

Scanning, isolation, and removal
If you do not want to download a complete antivirus software, there are other options available. You can run a free online antivirus scan. Leading IT security and antivirus software providers including Norton, and AVG offer free virus online scans. All you have to do is to download the executable file and run it on your computer, and a free online virus scan is initiated.

Advantages and features of virus scan
Following are some of the features and advantages of a free online virus scan.

● Can be run from all and any browsers that you may be using.

● Detection as well as removal of Malware in the form of viruses, Trojan horses, spyware, phishing emails etc.

● A good and potent virus scanner is always up to date and uses the newest heuristic detection and threat-detection algorithms available

● An online virus scanner scans even the archived files so that the virus threat is removed entirely and conclusively

● Easy registration and activation as the new virus scanners do not require you to enter any contact or personal information

● The latest antivirus can run effectively and proficiently on all operating systems

It is necessary that you install the best free virus scanner that has the feature of an antivirus scan or possess the inbuilt virus scanner to protect your PC and networks at all times.