Worm virus definition

Once they have access, they can then also steal confidential information and data. The most common way for Worm malware to spread is by email.

This is usually in the form of an attachment on and email. Once it is opened, it directs the device to a malicious website, which will then download the worm. It will then replicate onto the device and attempt to spread to other devices.

In some cases, it can spread by sending emails to the email addresses in the address book of the infected device. Designers of Worm malware are taking advantage of popular trends. Adversaries may use bootkits to persist on systems at a layer below the operating system, which may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.

Software that modifies a web browser's settings without a user's permission to inject unwanted advertising into the user's browser. A browser hijacker may replace the existing home page, error page, or search engine with its own.

These are generally used to force hits to a particular website, increasing its advertising revenue. This software often comes in the form of a browser toolbar and is received through an email attachment or file download. A class of malware designed specifically to automate cybercrime. Crimeware distinct from spyware and adware is designed to perpetrate identity theft through social engineering or technical stealth in order to access a computer user's financial and retail accounts for the purpose of taking funds from those accounts or completing unauthorized transactions that enrich the cyberthief.

Alternatively, crimeware may steal confidential or sensitive corporate information. Malicious attempts by one or more people to cause the victim, site, or node to deny service to its customers.

A computer file that contains a sequence of instructions to run an automatic task when the user clicks the file icon or when it is launched via a command. Applications for personal or business communication that are built around the concept of online presence detection to determine when an entity can communicate.

These applications allow for collaboration via text chat, audio, video or file transfer. The action of recording logging the keys struck on a keyboard, typically covertly, so that the person using the keyboard is unaware that their actions are being monitored. Data can then be retrieved by the person operating the logging program. A keylogger can be either software or hardware. Software that uses system resources to solve large mathematical calculations that result in some amount of cryptocurrency being awarded to the solvers.

There are two ways that mining can be performed: either with a standalone miner or by leveraging mining pools. Mining software relies on both CPU resources and electricity. Once a system has a miner dropped on it and it starts mining, nothing else is needed from an adversary perspective.

The miner generates revenue consistently until it is removed. The part of the data transmission that could also contain malware such as worms or viruses that perform the malicious action: deleting data, sending spam, or encrypting data. While packet headers indicate source and destination, actual packet data is referred to as the "payload. A type of malicious software that is used by cybercriminals to target point of sale POS terminals with the intent to obtain credit card and debit card information by reading the device memory from the retail checkout point of sale system.

POS malware is released by hackers to process and steal transaction payment data. The card information, which is usually encrypted and sent to the payment authorization, is not encrypted by POS malware but sent to the cybercriminal.

Software that a user may perceive as unwanted. This may include adware, spyware, or browser hijackers. Such software may use an implementation that can compromise privacy or weaken the computer's security. Companies often bundle a wanted program download with a wrapper application and may offer to install an unwanted application, in some cases without providing a clear opt-out method.

Programs that hide the existence of malware by intercepting i. Rootkits or rootkit enabling functionality may reside at the user or kernel level in the operating system or lower to include a hypervisor, master boot record, or the system firmware. Adversaries may use rootkits to hide the presence of programs, files, network connections, services, drivers, and other system components.

Anytime perceived trust is used to elicit information from groups or individuals, it is referred to as "social engineering. Software that aims to gather information about a person or organization without their knowledge, that may send such information to another entity without the consumer's consent, or that asserts control over a device without the consumer's knowledge.

Programs that systematically browse the internet and index data, including page content and links. These web crawlers help to validate HTML code and search engine queries to identify new web pages or dead links.

A type of destructive malware that contains a disk wiping mechanism such as the ability to infect the master boot record with a payload that encrypts the internal file table. Wipers render the attacked process or component useless to the end user. Cisco Annual Cybersecurity Report. This document is provided on an "as is" basis and does not imply any kind of guarantee or warranty, including the warranties of merchantability or fitness for a particular use.

Your use of the information on the document or materials linked from the document is at your own risk. Cisco reserves the right to change or update this document at any time. Computer worm. For Home View all Malwarebytes products. They may also seem a bit coldblooded because they can be remorselessly destructive.

A computer worm is a subset of the Trojan horse malware that can propagate or self-replicate from one computer to another without human activation after breaching a system. Naturally, you must be wondering what is a Trojan and how does it relate to computer worms? To keep it brief, a Trojan uses trickery and social engineering to deceive people into running it. For example, a Trojan may pretend to be legitimate software.

A worm is a type of Trojan because it normally relies on social engineering to attack systems. Some people think that a computer worm and computer virus are the same things because the two behave similarly. They may even use the terms like "worm computer virus" or "worm virus malware. The defining difference between a virus and a worm is that viruses rely on human action for activation and need a host system to replicate. Over the years, there have been some particularly devastating worms.

Some worms have caused billions in damage. Here is a brief list of some infamous ones:. Many of the symptoms of a computer worm are like that of a computer virus. For example, you may have a computer worm if your computer slows down, freezes, crashes or throws up error messages. You may also notice that files are missing or corrupted or that your hard drive's space is rapidly depleting inexplicably.

Additionally, you may see alerts from your firewall about a breach. Like other forms of malware — computer worms can be stopped with the right antivirus and anti-malware software and safe computing practices. Also, update your essential software regularly to shield your computer from vulnerabilities like the wormable Windows flaw and the like.

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