How does a computer virus spread?
The virus of the computer is a little similar to a corona virus, sometimes the symptoms are obvious and sometimes you can never notice the
symptoms until your computer is already damaged. But the computer virus can only be detected by the anti virus, but some viruses will show
some signs, so if you know how to detect it there will be some noticeable difference in the way your computer performs, once it’s showing those signs you should not wait till it will spread or else your computer will be damaged soon.
The definition of computer virus.
The virus of a computer is a malicious software or a form of malicious software that has a legitimate application code to reproduce by itself in order to spread its damaging effects.
Attackers are damaging your computer through taking control of it by deploying some types of malware or a virus. The virus has its own way
of targeting on which parts it would like to infect. Unlike the biological virus like flu, or HIV that are dependent on the cell in the human
body before it reproduce on its own, then it can start processing another infection on the body organism. The same with the computer virus,
it can’t work alone, it is accompanied with its code snippet that is the one inserting itself into some other computer applications. A soon as that infected application will run, it will start to execute the virus code, which results big damage to the computer.
People mostly used virus and malware interchangeably in the daily conversation as being the popular topic when it comes to taking care of
their computer. But virus in a strict sense is a type of malware that perfectly match to the definition. There are other main types which
Trojans, which masquerade as harmless applications to trick users into using them, there is also a what we called worms, which can be
reproduced and spread independently of any other application. This particular virus can be distinguished by its feature which is needing to infect first before it can operate other programs.
How the computer virus infects?
If your computer application has been infected by the virus, the virus will do its malicious work by providing the computer a good high-level
overview of how the process works. So it will normally go in this way, as it is usually requested by the user, the infected application will execute, and then the virus will be loaded into the CPU memory before the legitimate code can execute.
The virus will then propagates itself by infecting other applications on the host computer, inserting its malicious code wherever it can. The
resident virus does this to program as the computer opens, while the non-resident ones can infect the executing files even if they are not
working. Boot viruses are using particular pernicious technique at this stage, they are placing their code in the boot sector to the computer’s
system disk, ensuring that it will be executed even before the operating system fully loads, making it impossible to run the computer in a proper way.
The payload will start its executions once the virus has its hooks already in your computer, and that is the term of the part of the virus code that will do its dirty function as how the creator is designing it for.
It all includes many kinds of dirty things: viruses can scan your computer hard drive for banking credentials, log your keystrokes to steal
passwords, and turning your computer into like a zombie that launches a DDoS attack against the hacker’s enemies, or even encrypt your
data and demand a ransom to restore access. There are some other types of malware that can have similar payloads, there are ransomware worms DDoS Trojans and so on and so forth.
How do computer viruses spread?
During the pre=internet days, viruses often spread from computer to computer via infected floppy disks. The SCA virus, for example, is
spreading amongst Amiga users on disks with pirated software. Those were mostly harmless, but at one point there were about 40% of Amiga users were infected.
Nowadays, viruses are spreading through the internet. It is the applications that are being attacked by viruses through transferring the code
from computer to computer just like other applications. Some other viruses are carrying a logic bomb-code that ensures the virus’s payload
only executes at a specific time or under a certain conditions- the users or the admin may be unaware that their applications are infected and
will transfer of install them with impunity. Some viruses will hijack computer’s mail software to send and email out a copy for themselves, or they will also download it from the infected code repository or compromised app store.
What is very noticeable in all of these infection vectors is that they are requiring a victim to use to execute the infected application code.
Remember a virus can only execute and reproduce if its host application is running. Email is still a common malware dispersal method, this
is what most people are worrying about. Can the virus be obtained from opening an email? Email is just the initial way, by simply opening
the message is not much but by downloading and executing an attachment that’s have been infected with the virus code. That is the reason
why our professional anti virus pro are so insistent that you should be careful about executing email attachments, thereby, most email clients and web mail services include virus scanning features by default.
the infection of the virus, but most email clients and web mail services have a built-in security features that would prevent this from happening, so there is not a big worry about it.
The kinds of computer virus
The various types of viruses that you might be encountering, is arranged in a good breakdown by the Semantic, and it is categorized in
different ways. We already have discussed about resident and non-resident viruses, boot sector viruses, web scripting viruses, and so on and so forth. There are still few more of those that you need to know.
Like the macro virus which infects macro applications embedded in Microsoft office or PDF files. There are a lot of people who are so careful
in not opening any strange applications but they forget that some sorts of documents can themselves contain executable code for the virus.
One of the smart viruses is the polymorphic virus slightly changes its own source code each time it copies itself to avoid being detected by the computer’s antivirus software.
Be Always aware that these category schemes are based on different aspects of a virus behavior, in other words the virus can be of more than one category. Resident virus can also act same as polymorphic, in some instance.
Computer virus protection
The antivirus software is the most widely known product in the category of malware protection products. CSO has compiled a list of the top antivirus software for Windows, Android, Linux and macOS,
But still you need to be aware that antivirus is not an all in all solution, specially for big company business, for the more advanced corporate
networks, endpoint security offerings provide defense in depth against malware. It’s not only the signature-based malware detection that you
have to expect from antivirus, but also the anti-spyware, personal firewall, application control and other styles of host intrusion prevention.
though keep in mind that antivirus isn’t a be-all end-all solution. When it comes to more advanced corporate networks, endpoint security
offerings provide defense in depth against malware. They provide not only the signature-based malware detection that you expect from antivirus, but anti-spyware, personal firewall, application control and other styles of host intrusion prevention.
Another characteristic about viruses is that they generally exploit vulnerabilities in your operating system or application code in order to
infect your system and operate freely. If there are no holes to exploit, you can avoid infection even if you execute virus code. To that end, you
will want to keep all your systems patched and updated, in order to keep an inventory of hardware so that you will know what you need to protect, and performing continuous vulnerability assessments on your infrastructure.
Signs and symptoms that the computers is being infected by virus
How do you know that the virus has penetrated over your defense? Except for some viruses, like ransomware viruses are not keen to alert
you that they’ve compromised your computer. The same with biological virus wants to keep its host alive so it can continue to use it as an
accessory to reproduce and spread, but there are ways in which you can be aware that your computer has been infected. Norton has all the good lists for all the possible symptom which include:
Unusually slow performance
Unknown or unfamiliar programs that start up when you turn on your computer
Mass emails being sent from your email account
Changes to your homepage or passwords
If you suspect your computer has been infected, a computer virus scan is in order. There are plenty of free services to start you on your exploration: The Safety Detective has a rundown of the best.
Computer virus removal
Once a virus is installed on your computer, the process of removing it is similar to that of removing any other kind of malware — but that
isn’t easy. CSO has information on how to remove or otherwise recover from rootkits, ransomware, and cryptojacking. We also have a guide to auditing your Windows registry to figure out how to move forward.
If you’re looking for tools for cleansing your system, Tech Radar has a good roundup of free offerings, which contains some familiar names
from the antivirus world along with newcomers like Malwarebytes. And it’s a smart move is to always make backups of your files, so that if
need be you can recover from a known safe state rather than attempting to extricate virus code from your boot record or pay a ransom to sketchy Eastern European gangsters.
Computer virus history
The first true computer virus was Elk Cloner, developed in 1982 by fifteen-year-old Richard Skrenta as a prank. Elk Cloner was an Apple II
boot sector virus that could jump from floppy to floppy on computers that had two floppy drives (as many did). Every 50th time an infected game was started, it would display a poem announcing the infection.
Other major viruses in history include:
Jerusalem: A DOS virus that lurked on computers, launched on any Friday the 13th, and deleted applications.
Melissa: A mass-mailing macro virus that brought the underground virus scene to the mainstream in 1999. It earned its creator 20 months in prison.
But most of the big-name malware you’ve heard of in the 21st century has, strictly speaking, been worms or Trojans, not viruses. That doesn’t mean viruses aren’t out there, however — so be careful what code you execute.
If we own a computer we are always being reminded by the pop up message about renewal of antivirus, make sure you will not ignore it,
because viruses will surely damage your computer, renew your subscription before it expires, and then your computer will be safe to operate.
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