10.10.2019
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Table of Contents. 1. “A Computer Virus is a malicious software program “Malware” that can infect a computer by modifying or deleting data files, boot sector of a hard disk drive or causes a software program to work in an unexpected manner”. A computer virus resides on a host computer and can replicate itself when executed. Virus can steal user data, delete or modify files & documents, records keystrokes & web sessions of a user.
Computer Viruses Introduction A computer virus is a program that is designed. Common types of computers viruses Computer viruses can cause very serious damage.
It can also steal or damage hard disk space, it can slowdown CPU processing. Definition of Computer Virus “A computer virus is a program that may disturb the normal working of a computer system”. Virus attaches itself to files stored on floppy disks, USBs, email attachments and hard disks. A file containing a virus is called infected file. If this file is copied to a computer, virus is also copied to the computer. Activation of Virus When the computer virus starts working, it is called the activation of virus.
A virus normally runs all the time in the computer. Different viruses are activated in different ways. Many viruses are activated on a certain data. For example, a popular virus “Friday, the 13 th” is activated only if the date is 13 and the day is Friday. According to “Computer viruses cause billions of dollars’ worth of economic damage each year, due to causing systems failure, wasting computer resources, corrupting data, increasing maintenance costs, etc”.
Damages caused by virus Computer virus cannot damage computer hardware. IT may cause many damages to a computer system. A virus can:. A computer virus can damage data or software on the computer.
It can delete some or all files on the computer system. It can destroy all the data by formatting hard drive. It may display a political or false message very few times. Causes of Computer Virus The following are the main causes of a Computer Virus.
Infected Flash Drives or Disks Flash drives and disks are the main cause of spreading viruses. Flash drives and disks are used to transfer data from one computer to other. A virus can also be copied from one computer to other when the user copies infected files using flash drives and disks.
Email Attachments Most of the viruses spread through emails. Email attachment is a file that is sent along with an email. An email may contain an infected file attachment. Virus can spread if the users opens and downloads an email attachment. It may harm the computer when it is activated. It may destroy files on the hard disk or may send the virus automatically to all email addresses saved in the address book. Infected / Pornography websites Thousands of insecure websites can infect computer with viruses.
Most of the websites with pornographic materials are infected, so by visiting these websites the user’s computer also gets infected by virus. These websites are developed to spread viruses or other unethical material. The virus is transferred to the user’s computer when this material is downloaded. These websites may access the computer automatically when the users visit them.
Networks Virus can spread if an infected computer is connected to a network. The internet is an example of such network. When a user downloads a file infected with virus from the internet, the virus is copied to the computer. It may infect the files stored on the computer.
Pirated Software An illegal copy of software is called pirated software. Virus can spread if user installs pirated software that contains a virus.
A variety of pirated software is available in CDs and from the internet. Some companies intentionally add virus in the software. The virus is automatically activated if the user uses the software without purchasing license. Types of Computer Virus The following are some well-known viruses. CodeRed It is a worm that infects a computer running Microsoft IIS server.
This virus launched DOS attack on White House’s website. It allows the hacker to access the infected computer remotely. Nimba It is a worm that spreads itself using different methods. IT damages computer in different ways. It modified files, alters security settings and degrades performance.
SirCam It is distributed as an email attachment. It may delete files, degrade performance and send the files to anyone. Melisa It is a virus that is distributed as an email attachment. IT disables different safeguards in MS Word. It sends itself to 50 people if Microsoft Outlook is installed.
Ripper It corrupts data from the hard disk. MDMA It is transferred from one MS Word file to other if both files are in memory. Concept It is also transferred as an email attachment. It saves the file in template directory instead of its original location. OneHalf It encrypts hard disk so only the virus may read the data. It displays OneHalf on the screen when the encryption is half completed.
Protection from Computer Virus Virus infects computer system if latest and updated version of an Antivirus program is not installed. Latest Antivirus software should be installed on Computer to protect it from viruses. A computer system can be protected from virus by following these precautions. The latest and updated version of Anti-Virus and firewall should be installed on the computer.
The Anti-Virus software must be upgraded regularly. USB drives should be scanned for viruses, and should not be used on infected computers. Junk or unknown emails should not be opened and must be deleted straightaway. Unauthorized or pirated software should not be installed on the computer. An important way of protection against virus is the use of back up of data. The backup is used if the virus deletes data or modifies it. So back-up your data on regular basis.
There are some great softwares that can back up your data automatically. Freeware and shareware software from the internet normally contain viruses. It is important to check the software before using them. Your best protection is your common sense. Never click on suspicious links, never download songs, videos or files from suspicious websites.
Never share your personal data with people you don’t know over the internet.
Computer viruses can wreck havoc to the operations of the computer. A computer virus is a type of malware that is intentionally written to gain entry into your computer, without your knowledge or permission. It has the capacity to modify or replicate itself, in which case it will continue spreading. There are varying different types of computer viruses and their effects also vary widely. While some simply replicate themselves, others adversely affect the programs and consequently, the system’s performance.
This therefore underlines the importance of not assuming that the virus is harmless and leaving it in the system. It is important that you scan your computer for viruses once in a while, so that you can be sure about its protection. There are various types of computer viruses, classified in terms of techniques, origin, the types of files affected, damage, OS or Platform attacked, as well as the places they hide. It’s relatively hard to answer how many different types of computer viruses there are but below covers the main core concepts of the common types: Resident viruses: These are permanent viruses dwelling in RAM memory.
In this case, they would be in a position to overcome, as well as interrupt, all operations that the system executes. Their effects include corrupting programs and files that are closed, opened, renamed or copied. Overwrite viruses: These viruses delete information that is in the infected files. In this case, the infected files would be rendered totally or partially useless. Unfortunately, you would only clean the infected file by deleting it completely, therefore losing original content. Direct action viruses: This virus replicates itself, then acts when executed. Subject to satisfaction of particular conditions, the virus infects files located in the folders or computer directory.
Definition Of Computer Virus
It is also in directories specified in the AUTOEXEC.BAT PATH. In most cases, it is located in hard drive’s root directory and takes particular action when the computer boots. File infectors: This virus infects executable files or programs.
On running the programs, the virus would be activated, then be able to carry out its damaging effects. Most of the existing viruses are in this category. Boot viruses: This virus infects the hard disk’s or floppy drive’s boot sector. This would make the computer unable to boot. These viruses can, however, be avoided by ensuring that the floppy disks and hard drive is well protected.
Never start the computer using an unknown disk drive or floppy disk. Directory viruses: This virus alters the paths indicating a file’s location. In this case, when the infected program is executed, you will be running the program unknowingly, since the virus has moved the original program and file to another location. This therefore makes it impossible to locate the moved files.
Macro virus: This virus affects files created using particular programs or applications containing macros. The mini-programs increase their ability to automate some operations, in which case they would be performed as single actions.
The user would therefore be saved the trouble of executing them singularly. E-Mail Virus: Worth listing even if most are Macro viruses. Generally these kinds of viruses infect computers through social interaction with someone who e-mails the end user. They may be asked to verify a billing statement or look at an invoice attachement. Upon opening the attachment the macro is fired off and runs and infected the computer. Most macro viruses are easily stopped by simply keeping software up to date on computers. Ransomware: Ransomware is type of malicious software product that attempts to hold a computer for ransom.
This might be locking files, hiding files, changing permissions on files or encrypting files. In early ransome attacks files where often simply hidden from the viewers and a monetary payment was requested to un-do the changes.
This kind of attack was rather simple to resolve by doing a system restore to un-do the changes to those files. As Ransomware evolved they started to encrypt files from users which no system restore would be able to resolve. The core Windows files would be fully functional but personal files and folders would be changed leaving the end user with no access to those files unless a payment was sent to the make of the ransomware software. As Crypto currencies such as Bitcoin arrived on the market ransomware became more prevalent as makers could have people send them bitcoin to a wallet address which they then could send out to multiple wallets and make the tracing of the coins hard to follow. With the release of NAS hacking tools on the black market an increase in sophisticated ransomware attacks occurred in early 2017 including the wannaCry attack which affected hundreds of companies around the world including government agencies such as the British National Health Service. Browser Highjacks: The most common types of viruses seen in 2014 – 2015 that have a high impact on users are Browser Highjack viruses.
Generally this type of infection is not really a virus but something called PUP or Potentially unwanted software. In most cases these browser highjacks change the users home page and search settings in the web browser and often make it extremely hard to remove and restore the default settings. Often times these kinds of browser highjacks get installed from bundled software that may include free programs such as computer games or wall papers. First Known Computer Virus The first known computer virus appeared in 1971 and was called the Creeper virus. This specific virus targeted select main frame computers running TENEX. To delete this virus a program was created by Ray Tomlinson called the Reaper which was actually another virus whose sole purpose was to delete the Creeper virus. Essentially this was the second known computer virus but some also refer to it as the first anti-virus client.
John McAfee released the first version of a Virus Scanner in 1987 which kicked off the creation of McAfee antivirus. Virus Prevention The only solution to never risk getting a computer virus is to keep the computer disconnected from the internet and off which is not practical. That being said you have many options that can greatly reduce the risk of getting a computer virus. Keep your operating system up to date. Microsoft, Apple and Linux have updates that roll out on a regular basis.
Keeping your operating system up to date alone will stop the vast majority of known threats. The Wanna Cry ransomware is a good example of this. System affected by this virus were those running Windows XP which stopped having updates to the program because of newer replacements such as Vista, Windows 7, Windows 8 and Windows 10. Keep your web browser updated. Nearly all web browsers have an auto update feature that allows you to auto update your web browser. Popular browsers out there include, FireFox, Chrome, Safari and Edge (formerly known as Internet Explorer).
Keep your software programs updated. Programs such as Office, Adobe PDF, Flash are all targeted programs due to their wide user base. The more popular a program is the more it’s a target for exploits.
Safe Web Browsing. This is covered more in-depth in the Safe Web Browsing section. Basically don’t un-trusted websites and you will be 99% of the way there. Have an Active antivirus client installed that prevents virus infections and keep the program updated. Do not open e-mails with attachments from unknown senders. Even if it’s a know use caution as their e-mail could of been hacked. Anti-Virus Software Downloads There are a wide range of free anti-virus clients on the market Free Software Downloads.
Types Of Computer Virus For Kids
Microsoft Essentials. Malwarbytes Software. Many other free programs exist on the market such as Avast and AVG. They have light virus protection which does protect end users from most basic threats. There are of course many paid antivirus clients that do a fantastic job at protecting computers such as Norton, Trend Micro, Kaspersky, McAfee, G-data and on and on. There are also different tiers of protection within different antivirus clients. A general antivirus client will offer protection from virus and malware while an Internet Security Suit generally with include more robust security measures like a firewall, e-mail scanner and possibly a data backup solution like what is included in the Norton 360 security suite.
Virus Removal Options Hiring Someone The first more obvious one is hiring a professional to remove the virus for you. This can be a local repair shop or a remote computer repair company that can remote into your PC to remove the computer virus for you. In most cases these specialist will use freely available computer repair programs to scan your computer.
Manual removal is seldom needed unless there is a core file that an anti-virus program cannot detect and the professional can isolate the file and delete it manually. The added benefit to hiring a computer repair company is the peace of mind knowing the virus is fully removed from the computer.
Using Anti-virus Software Most people can still install software even when infected with a computer virus. Installing and running a full deep scan of a computer with anti-virus software that is updated often times will remove a computer virus. Virus Related Scams Virus related scams have been around for over a decade. A common scam is simply showing the end user a webpage that tells the user they have a computer virus. Scary wording is often used in an attempt to trick the user into panicking and then making a purchase. Simply closing down the web browser would stop the error messages. You now see this commonly played out on mobile devices with ads that say the user has several viruses found on their phone and they need to install an app to protect their phone.
The app is there simply to push ads constantly when you are browsing the web. Another popular scam going around where from fake antivirus programs. They would be installed on the users computer without the users permission and nearly cripple the computer from functioning. Strong wording would be used such as a keylogger installed that is tracking all the keys entered into the computer or that the persons bank account can now be accessed remotely.
There were hundreds of these fake antivirus programs going around a few years back but most of the holes have been patched security wise from Microsoft and thankfully government agencies around the world have cracked down on those making these fake virus programs and those who where marketing them. Safe Browsing Habits There is no full proof system out there to product yourself from getting infected with a virus. The first recommendation is to have an active antivirus client installed.
The next would be to avoid installing software from vendors you do not trust and only install software from trusted sources. Avoid websites that spawn lot’s of ads. Porn sites are a lot cleaner than they used to be but they still can carry lot’s of malicious code. Keep your plugging and extension updated and remove those you no longer use. Keep your web browser updated and if you still use flash be sure to always have that updated and remove the old flash version. When checking e-mail avoid opening attachments unless you fully trust the source and even then take caution as that persons e-mail account could of been hacked. 2 Step Authentication Many e-mail services and social accounts as well as banks now allow for 2 Step authentication.
This in it’s simplest terms means you need to have 2 pieces of information to gain access to the system. Often times this will be your password as well as a security code found that is unique to you that rotates every minute. This is often stored on the end users phone. While it may sound complicated they are simple programs to use and go a long ways in protecting your online accounts from hackers. After you enable 2 Step authentication on your first login you are generally asked if you want them to remember your device. If you are on your home computer you can say yes and you won’t have to enter in the second code every time. If you attempt to login on a different computer you will be challenged again with the second code and would need that to login.
Passwords It’s a good idea to have separate passwords for every account you have online. This means your facebook account will not have the same password as your bank account or e-mail account. It can be hard to keep track of dozens of different passwords which is why I recommend all users use a password management program like roboform or Lastpass. Protecting Your Smart Phone With smart phone use constantly on the rise more and more threats are being made for Smart Phones. Generally most users have little to worry about and by taking just a few extra measure you can protect you phone and privacy. It’s a best practice to always have your phone locked when not in use. This will stop someone from gaining access to your mobile device and messing with your personal setting and information.
Eric B Suhler
Only installing apps from trusted sources such as the App Store and Play Store. Taking caution to remove apps no longer in use on your phone as well as monitoring your phone activity after installing and app.
You may love a new game you just downloaded but if you start getting pop ups all the time when browsing the web normally there may be active code in that free app that is pushing advertising onto your phone. Those kinds of apps you should remove immediately.