Computer Virus

casison wrote:

How has the influence of the online world (the Internet, networks, bulletin board systems, and e-mail) affected the world of viruses?

Since November 1987 when the Internet Worm created by Robert T. Morris, Jr. wreaked over $100 million worth of problems on computers connected to the Internet, it has been obvious that having computers connected on a computer network increased the possibility of virus infections. That is not to say that networks are bad, in fact networks are becoming more and more essential and valuable all the time. It's just that being online on a network, a BBS, or dialed into a remote computer increases the possibility of contact with viruses.

What are the symptoms of a computer virus?

karldedeles wrote:

Is Trojan Horse A virus?

I think no because a Trojan Horse is full of as much trickery as the mythological Trojan Horse it was named after. The Trojan Horse, at first glance will appear to be useful software but will actually do damage once installed or run on your computer. Those on the receiving end of a Trojan Horse are usually tricked into opening them because they appear to be receiving legitimate software or files from a legitimate source. When a Trojan is activated on your computer, the results can vary. Some Trojans are designed to be more annoying than malicious (like changing your desktop, adding silly active desktop icons) or they can cause serious damage by deleting files and destroying information on your system. Trojans are also known to create a backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate.

karldedeles wrote:

What are the 3 types of viruses?

Here are 9 Computer Viruses that you should know about:

1. Boot Sector Virus.
Even though this virus has now become obsolete, it still pops out in one way or the other. This virus got attention when floppy disks were used to boot a computer. In modern computers, this virus could appear on the “Master Boot Record”. In the partitioned storage device of your computer, it is the first sector to take place.

However, thanks to the fact evolution of Internet, the threat of this virus is now mitigated.

2. Web Scripting Virus.
Similar to the hyperlinks that we used in Microsoft Word, many websites rest on codes to provide engaging content to their users. For example, since the trends of watching videos online have now become very popular – more than 2 Billion Videos are streamed on Facebook every day, these videos also execute a specific code.

These codes can be exploited and it is very troublesome to note that this exploitation has taken place on some very notable sites. All the hackers have to do it to leave a comment in the Comments Section of the website which contains that code. Thus, even without the Webmaster knowing it, the code gets exerted into the site.

3. Browser Hijacker.
Ever faced a problem where the homepage of your web page gets automatically directed to a particular site? Well, that is the most common way by which this ransomware hijacks your browser.

While its visual effects might epitomize the threat, this hijacker is nothing more than a tactic to increase income from web ads. However, if you still want to clean your computer from this virus, give Soft2Secure a go.

4. Resident Virus.
After inserting itself directing into the memory of your system, this virus has the capability to take a number of actions. One of its more troublesome features is its ability to run away. Leaving behind the file which was originally infected, this virus has the ability to run on its own.

5. Direct Action Virus.
Similar to the Vienna virus which shocked computers in 1998, this virus comes into action after you have executed the file. The load is delivered to your computer and the virus becomes active.

However, this virus has a limitation. It takes no action unless the file which is infected gets implemented again.

6. Polymorphic Virus.
One of the factors that epitomize the usefulness of this virus is its ability to evade. The Antivirus programs that are enabled on our computers detect the presence of any virus by detecting its code.

Polymorphic virus has exploited this limitation beautifully as it changes its code every time the infected file is executed. Thus, it becomes nearly impossible for any ordinary antivirus to track it down.

7. File Infector Virus.
Although the word “file” in its name might suggest otherwise, this virus does not take the help of files every time. In fact, the file is only the starting point as the file infector dwarfs the first file after which it re-writes the file.

8. Multipartite Virus.
If you have read carefully the aforementioned viruses, you might have noticed that they use two methods for their transmission. Either they use one method or a single payload is delivered.

However, this virus wants to claim both. Depending upon the operating system of your computer or the files that exist on your computer, it might use any of the two methods to spread.

9. Macro Virus.
Appearing in the form of a word document which seemingly links the user to pornographic websites, Melissa is one of the most known Micro Virus. Going one step further, this virus not only exploits the user but also his/her friends by mailing the copies of the infected virus document to the contact list.

If you are handling a website, you can also keep your website virus and malware-free using Sitelock.

If you feel that you know another significant type of virus, please feel free to let us know in the comments section.

karldedeles wrote:

What is Virus types of virus?

A computer virus is one type of malware that inserts its virus code to multiply itself by altering the programs and applications. The computer gets infected through the replication of malicious code.

Computer viruses come in different forms to infect the system in different ways. Some of the most common viruses are

Boot Sector Virus – This type of virus infects the master boot record and it is challenging and a complex task to remove this virus and often requires the system to be formatted. Mostly it spreads through removable media.

Direct Action Virus – This is also called non-resident virus, it gets installed or stays hidden in the computer memory. It stays attached to the specific type of files that it infect. It does not affect the user experience and system’s performance.

Resident Virus – Unlike direct action viruses, resident viruses get installed on the computer. It is difficult to identify the virus and it is even difficult to remove a resident virus.

Multipartite Virus – This type of virus spreads through multiple ways. It infects both the boot sector and executable files at the same time.

Polymorphic Virus – These type of viruses are difficult to identify with a traditional anti-virus program. This is because the polymorphic viruses alters its signature pattern whenever it replicates.

Overwrite Virus – This type of virus deletes all the files that it infects. The only possible mechanism to remove is to delete the infected files and the end-user has to lose all the contents in it. Identifying the overwrite virus is difficult as it spreads through emails.

Spacefiller Virus – This is also called “Cavity Viruses”. This is called so as they fill up the empty spaces between the code and hence does not cause any damage to the file.

#File infectors:
Few file infector viruses come attached with program files, such as .com or .exe files. Some file infector viruses infect any program for which execution is requested, including .sys, .ovl, .prg, and .mnu files. Consequently, when the particular program is loaded, the virus is also loaded.

Besides these, the other file infector viruses come as a completely included program or script sent in email attachments.

#Macro viruses:
As the name suggests, the macro viruses particularly target macro language commands in applications like Microsoft Word. The same is implied on other programs too.

In MS Word, the macros are keystrokes that are embedded in the documents or saved sequences for commands. The macro viruses are designed to add their malicious code to the genuine macro sequences in a Word file. However, as the years went by, Microsoft Word witnessed disabling of macros by default in more recent versions. Thus, the cybercriminals started to use social engineering schemes to target users. In the process, they trick the user and enable macros to launch the virus.

Since macro viruses are making a come back in the recent years, Microsoft quickly retaliated by adding a new feature in Office 2016. The feature enables security managers to selectively enable macro use. As a matter of fact, it can be enabled for trusted workflows and blocked if required across the organization.

#Overwrite Viruses:

The virus design purpose tends to vary and Overwrite Viruses are predominantly designed to destroy a file or application’s data. As the name says it all, the virus after attacking the computer starts overwriting files with its own code. Not to be taken lightly, these viruses are more capable of targeting specific files or applications or systematically overwrite all files on an infected device.

On the flipside, the overwrite virus is capable of installing a new code in the files or applications which programs them to spread the virus to additional files, applications, and systems.

#Polymorphic Viruses:
More and more cybercriminals are depending on the polymorphic virus. It is a malware type which has the ability to change or mutate its underlying code without changing its basic functions or features. This helps the virus on a computer or network to evade detection from many antimalware and threat detection products.

Since virus removal programs depend on identifying signatures of malware, these viruses are carefully designed to escape detection and identification. When a security software detects a polymorphic virus, the virus modifies itself thereby, it is no longer detectable using the previous signature.

#Resident Viruses:
The Resident virus implants itself in the memory of a computer. Basically, the original virus program is not required to infect new files or applications. Even when the original virus is deleted, the version stored in memory can be activated. This happens when the computer OS loads certain applications or functions. The resident viruses are troublesome due to the reason they can run unnoticed by antivirus and antimalware software by hiding in the system’s RAM.

#Rootkit Viruses:
The rootkit virus is a malware type which secretly installs an illegal rootkit on an infected system. This opens the door for attackers and gives them full control of the system. The attacker will be able to fundamentally modify or disable functions and programs. Like other sophisticated viruses, the rootkit virus is also created to bypass antivirus software. The latest versions of major antivirus and antimalware programs include rootkit scanning.

#System or Boot-record Infectors:

The Boot-record Infectors infect executable code found in specific system areas on a disk. As the name implies, they attach to the USB thumb drives and DOS boot sector on diskettes or the Master Boot Record on hard disks. Boot viruses are no more common these days as the latest devices rely less on physical storage media.

karldedeles wrote:

What are the symptoms of a computer virus?

1. Unexpected pop-up windows. Unexpected onscreen ads are a typical sign of a virus infection.
2. Slow start up and slow performance.
3. Suspicious hard drive activity.
4. Lack of storage space.
5. Missing files.
6. Crashes and error messages.
7. High network activity.
8. Email is hijacked.

karldedeles wrote:

Which virus is most dangerous for computer?

ILOVEYOU virus
10 Most Destructive Computer Viruses
ILOVEYOU. The ILOVEYOU virus is considered one of the most virulent computer virus ever created and it's not hard to see why. ...
Code Red. Code Red first surfaced on 2001 and was discovered by two eEye Digital Security employees. ...
Melissa. ...
Sasser. ...
Zeus. ...
Conficker. ...
Stuxnet. ...
Mydoom.

karldedeles wrote:

What's the worst computer virus?

Notable instances
Conficker.
Creeper virus - The first malware that ran on ARPANET.
ILOVEYOU.
Leap - Mac OS X Trojan horse.
Shamoon a wiper virus with stolen digital certificates destroyed over 35,000 computers owned by Saudi Aramco.
Storm Worm - A Windows trojan horse that forms the Storm botnet.

karldedeles wrote:

What harm can a computer virus cause?

Damage caused by malware. The damage caused by a virus which infected a home computer or a corporate network can be different – from insignificant increase in outgoing traffic (if a computer is infected by a Trojan sending out spam) to the complete network breakdown or the loss of critical data.

karldedeles wrote:

What is Virus types of virus?

Multipartite Virus – This type of virus spreads through multiple ways. It infects both the boot sector and executable files at the same time. Polymorphic Virus – These type of viruses are difficult to identify with a traditional anti-virus program.

karldedeles wrote:

Are computer viruses dangerous?

Viruses are harmful for computers, laptops, mobiles for many factors such as they can destroy many files, hide files. ... Some viruses are to danger and they will destroy your complete computer system.

karldedeles wrote:

What is the most common computer virus?

Common Malware Types: Cybersecurity 101
Bug. ...
Ransomware. ...
Rootkit. ...
Spyware. ...
Trojan Horse. ...
Virus. A virus is a form of malware that is capable of copying itself and spreading to other computers. ...
Worm. Computer worms are among the most common types of malware. ...
Spam. Spam is the electronic sending of mass unsolicited messages.

karldedeles wrote:

Is Trojan Horse A virus?

Trojans are also known to create a backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate.

karldedeles wrote:

What are the types of computer virus?

9 Types Of Computer Viruses That You Should Know About – And How To Avoid Them
Boot Sector Virus. ...
Web Scripting Virus. ...
Browser Hijacker. ...
Resident Virus. ...
Direct Action Virus. ...
Polymorphic Virus. ...
File Infector Virus. ...
Multipartite Virus.

karldedeles wrote:

What are the 3 types of viruses?

Three types of malware: Viruses, worms and Trojans
Virus. A computer virus can automatically create and install a copy of itself on a computer's files, and – like a virus in humans – it can spread from computer to computer. ...
Worm. Much like viruses, worms can automatically replicate and infect multiple files. ...
Trojan.

karldedeles wrote:

What is a computer virus name its types?

A computer virus is a type of malicious software that, when executed, replicates itself by modifying other computer programs and inserting its own code. When this replication succeeds, the affected areas are then said to be "infected" with a computer virus.

Q. What is difference between virus and worm?

karldedeles wrote:

Q. What is difference between virus and worm?

An important distinction between computer viruses and worms is that viruses require an active host program or an already-infected and active operating system in order for viruses to run, cause damage and infect other executable files or documents, while worms are stand-alone malicious programs that can self-replicate.

greymarkb wrote:

What is a quick and deep or full antivirus scan?

A quick scan checks common areas for computers viruses. Scanned areas can include the computer memory and common areas of the hard drive, including the temporary Internet files and the operating system directory. Typically a quick scan takes less than 30 minutes to complete.

A full scan checks every area of the computer, including memory, hard drives and sometimes any external devices connected to the computer, like external hard drives and USB flash drives. Because the full scan checks everything, it takes longer to perform the scan. Depending on how much memory and hard drive space a computer has, it could take 30 minutes to several hours to complete a full scan.

Netthan Baltazar wrote:

If I have a firewall, do I need an antivirus?

Yes. A firewall will not protect you from viruses and other malware. ... If you want to truly protect your computer from potential threats, we suggesting having both a firewall and antivirus program installed on your computer. Or, at a minimum, we recommend that firewall functionality be enabled on your router.

Amerodin Azis wrote:

Is it ok to have more than one antivirus installed?

No. We highly recommend that only one antivirus program be installed on your computer. If you're dissatisfied with the antivirus program you currently have installed we suggest that it be uninstalled, and a new antivirus program installed. Having more than one antivirus on the computer can cause many different issues. Often the most common issue being a confliction between the different antivirus programs causing your computer to become unprotected.

Netthan Baltazar wrote:

What is a virus definition?

a piece of code that is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data.

Amerodin Azis wrote:

Do antivirus companies create computer viruses?

No. Antivirus companies know the risks involved when dealing with computer viruses and the potential dangers of viruses getting out in the wild. The whole concept of antivirus companies creating viruses is a myth, urban legend, and a conspiracy theory.

greymarkb wrote:

How do you know if you have a virus?

1 – Your computer is slow to shut down or boot up into Windows.

2 – It won’t shut down at all without pressing and holding the power button.

3 – You have all kinds of pop-ups and browser windows opening all by themselves at random times.

4 – You notice that your web browser has one or more toolbars that you don’t remember installing.

5 – Your web browser’s default search provider and/or start page have changed all on their own.

6 – You’re unable to load certain websites and/or your browser is re-directed to websites that you have no desire to visit.

7 – You get a warning that you need to update your antivirus software, but it comes from a “security” program that you never installed on your PC.

8 – You receive a notice that Microsoft or some other “security” company has detected malware on your computer and you need to call them or visit their website and pay them to remove it for you. This notice itself is malware.

Important: As explained in this post, neither Microsoft nor Apple will ever call you or send you an email stating that your PC has a virus. They just won’t.

9 – You receive a message that your drivers are out of date and you need to use a third-party app to update them (and pay some company for the privilege of using it).

Important: You should never have to pay for driver updates, and if someone asks you to it’s almost always a scam. Read this post for more information on that.

10 – Your computer hangs up and becomes unresponsive at random times.

11 – Programs run so slowly that you dread using your computer.

12 – The system operates so erratically that you have trouble typing or using the mouse.

13 – Your computer’s fans run constantly at breakneck speed (you can actually hear the fans running faster than they should).

Netthan Baltazar wrote:

What is the difference between a virus and malware?

Let's start with the differences between "viruses" and "malware." Viruses are a specific type of malware (designed to replicate and spread), while malware is a broad term used to describe all sorts of unwanted or malicious code. Malware can include viruses, spyware, adware, nagware, trojans, worms, and more.