Users of computer, smartphone, and tablet are faced with an increasingly growing threat due to computer viruses and malware.

There are many types of malware on the Internet that cause direct or indirect harm to individuals and users. These malwares are called Malware.

Malware, which is short form of “Malicious Software”, is the general name of viruses, trojans horses, trojans and other unwanted malicious software.

Malwares are this software having the intentions of doing harm to computer systems, stealing our information, and having other ill-intentions.

We can summarize this malicious software as computer viruses, trojans, worms, spyware and keyloggers.

Computer viruses are software programs that are designed to prevent the operation of the computer, to save, corrupt or delete data, or to cause slowdowns or other problems by spreading themselves over the Internet to other computers. Viruses can enter any computer in different ways and cause undesired results and damages in these computers.

According to the National Institute of Standards and Technology (NIST), the first computer virus called "Brain" was developed in 1986. Two brothers, tired of customers stealing software from their companies, suggested that they have designed in order that it affects the boot sector of disks of the software thieves. When the discs were copied, the virus was also spread.

How can you notice that your computer has a virus?

•  If your computer has become unusually slow.
•  If your new or previously used external disks are no longer working,
•  If weird and numerous messages pop up on your screen,
•  If the software you have been using crash or run very slowly,
•  If the names, file sizes, saving dates of your documents or files change by themselves,
•  If your file 'download' and 'upload' speed on the Internet has dropped too low,
•  If there are weird movements on your monitor, CAUTION !!!

Ways to protect against viruses

• Never open an email attachment from someone you don't know unless you know exactly what is included in a file attachment.
• You must have an anti-virus program and a firewall on your computer. There are many anti-virus programs to protect against viruses. For example; AVAST, NOD 32, KASPERSKY, PANDA AND SYMANTEC etc. These programs can include a firewall as an internet protection package, in addition you can use the firewall of your operating system.
• Always keep your antivirus software up to date. Out-of-date anti-virus software will never be useful for your security. Because viruses are constantly updating themselves.
• Scan such hardware as hard disk, cd, flash disk etc. with anti-virus software before uploading information to, or sending data from such hardware to your computer.
• Always keep your operating system up to date and use genuine (licensed) software programs.
• Do not spend much time while browsing web pages you do not know and do not download too many programs / files to your computers from these pages. Make definitely sure to scan the downloaded files with anti-virus software on your computer. If you do not want to be bound by a single virus program, you can upload the downloaded file to the system in the address of https://www.virustotal.com/ and perform online scanning with all anti-virus software.

Trojans are malware that appear to be useful but actually cause harm. How did the Trojan horse in mythology look like a gift and actually carry the soldiers who would invade the city of Troy; these Trojans are computer software that also look like as if they were useful software.

Trojans become active when the file of program, to which they are attached, is run and spread by users copying them. It is not easy to detect them like ordinary viruses. They show their effects after your computer is infected. Trojans can slow down your internet, delete or modify the files on your computer.

 

Ways to Protect against Trojans

• If you receive an e-mail from someone you do not know or if you receive an e-mail having an attachment you do not know, never open it. As an e-mail user, always confirm the origin of the mail.
• Make sure that attachments are not opened automatically while you make your e-mail settings. Some e-mail service providers offer software that can scan e-mails against viruses before opening its attachments.
• Operating systems release updates to protect their users from certain threats. Software developers such as Microsoft release patches (updates) to fix vulnerabilities that trojans or viruses can exploit. If you keep your system updated by installing these patches, your computer will be more secure.
• It will be helpful to restrict the use of some programs, which are peer to peer (P2P), or share the local network, such as µTorrent, Kazaa, LimeWire, Ares and Gnutella. Because these programs are generally unprotected in terms of the spread of software such as viruses or trojans.

 

The worm, like other malicious software, is designed to copy itself from one computer to another; however, it does this automatically, unlike trojans. When the Trojan virus entered the computer, it waits for the program, with which it is entered to the computer, to be run, and if the program is not run, the trojan horse cannot be activated on the computer.

Furthermore, the Trojan directly damages the computer's operating system. Worm does not do any harm, but only reports, as a report, the websites you entered, the user names and passwords you entered, the programs you downloaded, that is to say, everything you do on the computer. The worm initially takes control of the properties on the computer, which transmit files or information. Once the worm enters your system, it can travel on its own. The biggest danger of worms is their ability to reproduce themselves in large numbers.

For example, a worm can send its copies to anyone in your e-mail address book, and then their computers can do the same. A worm usually spreads without user action and distributes complete copies of itself (possibly modified) across networks. A worm can consume memory or network bandwidth, which can cause the computer to crash.

Source: https://www.guvenliweb.org.tr/