Define worm viruses

A virus typically attaches itself to a program, file, or the boot sector of the hard drive. When the infected application or file runs in the computer, the virus activates and executes in the system. It continues to replicate and spread by attaching replicas of itself to other files and applications in the system. A virus spreads when the infected file or program migrates through networks, file collaboration apps, email attachments, and USB drives.

Once a user opens the infected file or program, the vicious cycle repeats itself all over again. Typically, the host program continues to function after the viral infection, but some viruses overwrite entire programs with copies of themselves, which corrupts and destroys the host program altogether. If your operating system is up-to-date with the most recent version, you are more likely to be protected from worms and other malware. Manufacturers are constantly on the lookout for vulnerabilities, and they often release patches that address them in operating system updates.

A virus attaches to a file or program, and it gets sent to another computer because that file or program is transferred. In other words, a virus goes along for the ride, using a host file or application to get from one place to another. A worm also spreads from one computer to the next, but it does this all on its own, without the help of an additional file or program.

A Trojan horse is very different from both a worm and a virus, particularly in how it is spread. A Trojan will look like a legitimate program, but when it is executed, it infects your computer, causing different kinds of harm.

Trojans also have the ability to set up backdoors—similar to worms—that allow a hacker to gain access to your system.

The Fortinet FortiGuard antivirus security service stops worm attacks through advanced threat and malware detection engines that thwart both existing and new threats from penetrating your network. With FortiGuard, you can reduce your threat management expense. It automatically updates every hour, making sure you have the most recent protective measures guarding your digital resources.

Worms are transmitted through vulnerabilities in software. Once the worm is on the device, it infects it without the user being able to tell. Worms spread on their own, without the help of additional software or files. A worm is often introduced to a computer or network through a link or file sent through an email, chat, or other online communication. Skip to content Skip to navigation Skip to footer. What Is a Worm Virus?

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. The official Malwarebytes logo The official Malwarebytes logo in a blue font.

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Partners Explore Partnerships. Partner Success Story. Resources Resources Learn About Cybersecurity. When the host code is executed, the viral code is executed as well. Normally, the host program keeps functioning after it is infected by the virus. However, some viruses overwrite other programs with copies of themselves, which destroys the host program altogether.

Viruses spread when the software or document they are attached to is transferred from one computer to another using the network, a disk, file sharing, or infected email attachments.

Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage. In contrast to viruses, which require the spreading of an infected host file, worms are standalone software and do not require a host program or human help to propagate. To spread, worms either exploit a vulnerability on the target system or use some kind of social engineering to trick users into executing them.

A worm enters a computer through a vulnerability in the system and takes advantage of file-transport or information-transport features on the system, allowing it to travel unaided.

More advanced worms leverage encryption, wipers, and ransomware technologies to harm their targets. A Trojan is another type of malware named after the wooden horse that the Greeks used to infiltrate Troy. It is a harmful piece of software that looks legitimate. Users are typically tricked into loading and executing it on their systems.

After it is activated, it can achieve any number of attacks on the host, from irritating the user popping up windows or changing desktops to damaging the host deleting files, stealing data, or activating and spreading other malware, such as viruses.

Trojans are also known to create backdoors to give malicious users access to the system. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate. Trojans must spread through user interaction such as opening an email attachment or downloading and running a file from the Internet. Bots often automate tasks and provide information or services that would otherwise be conducted by a human being.

They may also be used to interact dynamically with websites. Bots can be used for either good or malicious intent. In addition to the worm-like ability to self-propagate, bots can include the ability to log keystrokes, gather passwords, capture and analyze packets, gather financial information, launch Denial of Service DOS Attacks , relay spam, and open backdoors on the infected host.

Bots have all the advantages of worms, but are generally much more versatile in their infection vector and are often modified within hours of publication of a new exploit.

They have been known to exploit backdoors opened by worms and viruses, which allows them to access networks that have good perimeter control. Bots rarely announce their presence with high scan rates that damage network infrastructure; instead, they infect networks in a way that escapes immediate notice.

Advanced botnets may take advantage of common internet of things IOT devices such as home electronics or appliances to increase automated attacks.

Crypto mining is a common use of these bots for nefarious purposes. Advanced malware typically comes via the following distribution channels to a computer or network:. A set of stealthy and continuous computer hacking processes, often orchestrated by a person or persons targeting a specific entity. An APT usually targets either private organizations, states, or both for business or political motives.

APT processes require a high degree of covertness over a long period of time. The "advanced" process signifies sophisticated techniques using malware to exploit vulnerabilities in systems.

The "persistent" process suggests that an external command and control system is continuously monitoring and extracting data from a specific target.