Maybe you are dealing with a Virus or Malicious code right now and your quest for information on this subject has brought you to this very site.
Below we have listed some of the most common forms of viruses, how they are spread, as well as information on Trojans and Worms and how to deal with them.
What is a Virus?
A Virus on a computer is a program that attaches to another file or program, usually an executable file and is self replicating. The virus is not usually active until the infected file or program is opened. A computer virus can be spread from one computer to another replicating itself on each computer. A Computer Virus is only spread through human action, (such as running an infected program or mailing such a program). There are different levels of severity in computer viruses. Some are mainly annoying, causing your computer to slow down while others can permanently damage your Hardware, files, software and system security.
Viruses were originally spread through Diskettes or floppy disks but now are most commonly spread through the internet. There are many ways to transfer a virus on the internet. Some methods include Spam email, shared online files like Music and Images, free downloads, plugins, free scans or just by trying to close a popup on an unfamiliar site. The methods used to spread malicious code and viruses are many and grow more and more sophisticated. That is why it is important to have up to date internet security or antivirus software on your computer. Unfortunately, while anti-virus software and internet security software catch a large amount of common viruses, malware, trojans and worms, they don’t protect you from all threats. There are many Viruses that are designed to go undetected by Antivirus software i.e. the Redirect Virus and some viruses that are constantly changing and not detected, such as a Polymorphic Virus. That is why it is important to be careful when entering an unfamiliar websites and never open email from an unfamiliar source.
Boot Sector Virus
The Boot Sector Virus is more of an old school virus that originated with floppy disks. The Virus would be introduced to the computer via an infected Floppy Disk. The Virus would then replicate to the Boot Sector where the disc type and format are stored . The virus would then move on to the Hard Drive. Then every time a new disk was introduced to the drive the virus would replicate to the new floppy disk. Today Floppy disks are rarely used so a Boot Sector Virus is transmitted in other ways and targets the operating system. Most Anti-Virus Software have no problem eliminating this Virus.
Redirect Virus or Browser Hijack
The Redirect Virus (AKA Browser Hijack, Google Redirect Virus, Hijack Virus, etc…) is a common occurrence on the internet. This Virus is spread many different ways including voluntary download. There are many purposes for this Virus but the main action is to direct your browser to sites the hacker wants you to go to. Often your search results will look fine but when you click the link you will be brought to a site that has nothing to do with your search. These may just be ad sites or products sites the hacker wants you to buy or it could be more sinister. Often these sites look to install malware on your computer. The intent is much more harmful than selling you something. These sites may instal Spyware or Trojans seeking to capture personal and financial information for the hacker.
Removing the Redirect Virus is a big problem. The Redirect Virus hides successfully from most anti-virus software. Often the Security Software will find and eliminate the malware that was installed on your computer but not the Redirect Virus. After a short time the Redirect Virus will send your browser to the bad sites to reinstall the malware, starting the whole process over.
For successful removal of the Redirect Virus, you need a program or system specifically designed to remove it. Click here for more info.
File Infector Virus
The File Infector Virus attaches itself to program files with the extensions .exe or .com. When the host program is activated the virus acts. The virus can be crafty and go unnoticed. It often alters only part of a file or none of it, only replacing unused files in a program. The File Infector Virus is one of the most common viruses and is usually detected by Antivirus Software.
A Polymorphic Virus has the ability to change and Morph its appearance thus making it very difficult to detect. The inner workings and function of the virus remain in tacked while the outer structure is ever changing. A Polymorphic Virus often changes its’ code every time it is enacted. Often this Virus uses an encryption algorithm that will alter itself when certain conditions occur.
Anti-Virus Programs search for specific codes to detect viruses. With a Polymorphic Virus ever changing its’ code, it is very difficult to detect.
It is important to stay current on your Anti-Virus Software updates. They are continually adding new IDs to new and new versions of old viruses.
By the commissioning of the 32-bit operating system Windows 95, it became possible to include macros. A Macro Virus is therefore also called a 32bits-virus. A macro is typically used to change font or to automatically insert a piece of text. However, when a word macro includes a virus, it enacts the virus immediately when the file is opened. This Virus can also be transmitted from other software packages in MS Office that support macros. Macro viruses work as an independent platform, so if the virus is included in an attachment from a windows pc, it can also works on a Mac.
The most popular version of this virus was the Melissa Virus. This Macro Virus exploited Word’s link to Microsoft Outlook and would mail itself to everyone on the hosts mailing list. Ouch!
Most Anti-Virus Software have no problem finding this Virus.
A Multipartite Virus or Multi-Part Virus attacks you system in several ways at once. It will attach to the Boot Sector and your Executable files at the same time. While the virus attaches to your Boot Sector files it attacks your system files. When it attaches to your system files i.e. your .exe and .COM, files it attacks your Boot Sector files. The only way to get rid of this Virus is all at once. Otherwise it will just continue the ping pong game until it is fully removed.
A Resident Virus is one that remains in the system memory after it is executed. In other words, the infected file is installed and executed on your computer. The virus imbeds itself in the system memory and acts independently from the infected file. So even when the infected file is detected and removed, the Virus remains in the system memory.
Direct Action Virus
The Direct Action Virus is another old school type virus and is not seen as much today. The Direct Action Virus is a One Trick Pony that only opens when the infected file is opened. It then lays dormant unless the infected file is opened again. This type of Virus is easily detected with AntiVirus (AVS) Software.
Web Scripting Virus
The use of complex code in order to execute and play video on websites has opened up a whole new set of script to be exploited with viruses and malware. These are known as Web Scripting Viruses. Most of the time these scripting viruses are not forcibly introduced to a system but innocently introduced through code uploaded without the webmaster being notified.
Although a Web Scripting Virus can seriously compromise the security of your system. The Web Scripting Virus can be easily removed using your free Microsoft tool.
Your Microsoft Tool software is easy to run and comes defalt with windows Vista, Windows 2000, and windows 7. To use your Microsoft Tool to remove a suspected Web Scripting Virus, simply follow these steps.
- Select the RUN button
- Go to the start menu and type MRT.
- Click next
- Select Full Scan or Quick Scan
- Click next
- Observe the prompts
- Click finish
- Restart the machine.
What is Spyware?
The sole purpose of Spyware is to collect information on a users computer without the user knowing it. While Spyware is considered a Malicious Software it is also used by computer owners in the corporate world to monitor employees on shared computers. Spyware can be designed to collect almost any data on a computer such as Key logging, browsing and surfing habits as well as personal information. Spyware is also sometimes used by parents to monitor children’s internet habits.
Unfortunately Spyware is also used as Malicious software. Spyware can be very hard to detect and collect almost any kind of information. When installed on an unsuspecting users computer Spyware can be used to capture personal and financial data. Spyware used as Malware can be a huge security threat to any computer system.
What is a Computer Worm?
A Worm is very similar to a Virus by design and spreads from computer to computer. One big difference though is that a worm needs no human help, it will spread all on its’ own. A worm takes advantage of information and file transfer operations on your computer which allows it to travel and replicate by itself.
An example of the effects of a Computer Worm is one that self replicates on your computer, then access your contact list and emails everyone on it. Not only do all your contacts get multiple emails from you, but when they open these emails the worm spreads to their computer and continues the same process of mailing itself to all their contacts and so on, and so on.
The continued replication of a Worm on your computer can eventually eat up all your memory and slow your computer to a crawl or worse, shut it down. In the case of the Blaster Worm, the worm dug its way into the system and allowed hackers to then control the host computer remotely
What is a Trojan Horse?
Much like the mythology it is named after a Trojan Horse is not what it seems to be. The Trojan is introduced to a system disguised as a legitimate file or software program. Unlike Worms and Viruses, Trojans do not reproduce or self replicate. Instead, once it is opened the devastation begins. Trojans are sometimes just an annoyance, altering your desktop or damaging and deleting files. Trojans are also known to compromise your system by opening a back door, allowing malicious users to access sensitive personal files and information. Not only can this compromise the security of your personal computer system but all the accounts you have online. Yikes!!!
How do I protect myself from all these Viruses, Worms and Trojans?
The best way to protect your self from all these menacing malicious codes is to be very careful about anything you download. Don’t open emails from people you don’t know, (No matter how tempting the offer). Keep your Anti-Virus Software and Internet Security software up to date. Check for updates once a week. If you think you have a Redirect Virus, take care of it as quickly as possible before it gets more serious.
This site has a full range of Software reviews available under each category listed in the menu bar.
As well as Categories such as Anti-Virus Software, we have a Featured Software page that list Best User Reviewed Software from all categories.