5 Types of Viruses in Computer
A computer virus is a type of malicious software that is designed to replicate itself across computers and networks. It is capable of performing various malicious activities such as damaging computer systems, stealing data, and disrupting normal operations.
Since 1986 when the first virus was released, viruses have caused havoc across computers and electronic devices. You know a virus is present when programs slow down unexpectedly or you receive error messages, or files simply disappear without explanation.
Computer viruses can be spread in a number of different ways, including via email, downloads, and even through removable storage devices such as USB drives. There are several different types of computer viruses, including boot sector viruses, file infectors, macro viruses, and Trojans. Each type of virus has different characteristics which can make them more or less dangerous.
Some of the most common types of viruses include:
Direct Action Virus
Computer viruses are sneaky programs that secretly modify files and applications without user knowledge, infiltrating private data without their owners knowing and slowing down device performance. Once activated, they can steal personal information or slow it down significantly as well as display political, humorous or threatening messages on screen, spam your contacts via email and even rewrite files on hard drives connected to same network and infect other computers on that network.
Some computer viruses remain dormant within your memory, only emerging when opening certain files or programs – these are called resident viruses. Their more aggressive cousin, known as multipartite virus, attacks both files and boot space simultaneously; an even worse strain known as overwrite virus erases existing program code to insert its own malicious payload instead.
Polymorphic viruses, which mutate each time they replicate to avoid detection by anti-malware and threat detection products that rely on specific malware signatures, and network viruses which spread quickly via peer-to-peer file sharing services like Dropbox or SharePoint are more difficult to combat than their counterparts because of their rapid spread.
Resident Virus
Resident viruses reside in your computer’s memory and can infiltrate files even when their originating program no longer runs, making them one of the most dangerous types of malware. They’re difficult to remove, making them one of the deadliest threats possible; fast infectors spread rapidly while slow infectors attack gradually causing significant damage; some reside as attachments on antivirus software which allow them access to every file the software scans allowing for quick attack by these viruses.
Common symptoms of an infection with polymorphic viruses include unusual error messages. Restarts on its own or abrupt shutdowns are also symptoms; polymorphic viruses can hide in images, videos and layouts used by malicious websites; furthermore they can rewrite themselves over and over. Polymorphic viruses are difficult to detect as their signatures and decryption routine can change to bypass antivirus programs. They even alter code within compromised programs to rewrite themselves continuously!
Multipartite Virus
Resident viruses are known for taking up space in your computer’s memory and eating away at it, rendering your device inoperable and creating incessant memory consumption. Their presence can be identified through messages like “running low on memory” or “unable to connect to internet”.
Boot sector viruses are another type of threat that evade antivirus software, infiltrating your master boot record (MBR) before infecting program files and corrupting memory at will. Once inside, they can rapidly unleash destructive payloads at any moment.
Multipartite viruses, also referred to as hybrid viruses, combine elements from file and boot infectors into one powerful hybrid virus that strikes quickly. Such fast- acting threats infiltrate both your boot space and program/executable files at the same time for maximum damage – with Ghostball being perhaps the best-known example; others include Flip and Invader as examples of multipartite threats.
Polymorphic Virus
Imagine an ever-evolving cyber threat, designed to remain undetected and undermine your system – that is exactly what polymorphic viruses do and they pose one of the greatest dangers to data security.
Polymorphic malware strikes through various means, including social engineering – where hackers use deceptive tactics to induce users into downloading or executing the virus through free software downloads, misleading advertisements and email attachments. Once infiltrated, polymorphic malware spreads by exploiting vulnerabilities in file-sharing protocols, remote desktop services or outdated software to gain unauthorised entry to networks.
Once installed on its target system, this virus uses its code to mutate and rewrite itself each time it infects new targets, remaining undetected even by antivirus programs that attempt to identify and eradicate it.
Antivirus software that recognizes malicious code and patches it quickly is key in protecting yourself against polymorphic viruses, along with backing up files regularly and not clicking suspicious links or attachments. Finally, remember to change passwords frequently but not so frequently that attackers can guess or crack them easily.
Boot Sector Virus
Boot sector viruses infiltrate physical parts of storage devices that your computer relies on for starting up, such as DOS Boot Sector or Master Boot Record (MBR).
Once infected, these older viruses may result in applications slowing down significantly or performance delays; eventually your hard disk could even become inoperable!
Polymorphic malware can be very dangerous. It evades antivirus detection by altering its code each time it replicates, making it harder for antivirus software to spot. Polymorphic viruses like the notorious VirLock display ransom notes demanding money before releasing files.
The Elk Cloner virus created by 15-year-old high school student Richard Skrent was non-malicious but inspired malicious programmers to create boot sector viruses with similar ideas of infecting computers at boot up. Boot sector viruses often spread via write-enabled floppy disks but now infiltrate any storage device and perform harmful acts such as overwriting data, corrupting files, displaying funny or political messages on screen, spamming email contacts with spam emails, stealing personal data and making machines unusable altogether.
Conclusion
It is important to be aware of the different types of viruses out there and to take steps to protect your computer from them. Installing antivirus software and keeping it up-to-date is the best way to keep your computer safe from viruses.