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What is a Computer Worm?

The worm is a malicious computer program that can replicate itself for the purpose of circulating into multiple computer systems. It is a standalone program that depends on security vulnerabilities to gain access to the target computer.

The most significant fact of a computer worm is its characteristics of its own replicating without even the host computer command. But, worms are different in function and purposes compared to computer viruses and malware.

The minimum effect of a computer worm can be consuming high bandwidth where virus drastically affects the system, files, and programs- modify and corrupt them. At a higher stage, computer worms can also do something similar to modifying and deleting computer files with a certain limitation. Worms have the ability to change and remove files, as well as insert other malware onto a file system, not in an operating system.

What Does Computer Worm Mean?

Worm operates autonomously on the infected host computer. But, the virus embeds the code in the computer and relies on carrying it out to the attack surface. A worm can simply copy itself and infect other computers on the network.

Although some worms need user engagement to spread, including clicking on a malicious link, others might spread quickly without it. Everything that is required is for the worm to become activated on a system that has been infected.

Computer worms are often set as encrypted files, making them difficult to detect and erase. However, antivirus programs can usually detect simple worms, sophisticated worms can encrypt and backup themselves within a file registry. It is fascinating that removing a worm may require a complete system wipe.

Computer Worm History

The earliest worm programs were created to make it easier to use a network. In 1971, Bob Thomas created the Creeper program that might be considered the first worm.

Creeper was a worm, which replicates and distributes to other computers to connect the computers of Digital Equipment Corporation (DEC) with ARPANET, the first packet-switched Wide Area Network (WAN).

Creeper wasn't the kind of malware we identify with today's computer viruses; all it did was show an intriguing message. It didn't do anything harmful like file-encrypting, data comptonization, or stealing.

Computer researchers John Shock and Jon Hepps started testing worm algorithms in the 1980s at Xerox's Palo Alto Research Center.

Later, The Morris Worm disrupted the Internet in November 1988, making front-page news for nearly a week. When reporters discovered that there was no picture to communicate the worm to the public viewing audience, the media coverage was severely harmed.

In 2009, the Conficker worm allegedly established a secure, global cybercrime infrastructure. The worm gives its developers the ability to install any program on affected computers automatically.

Conficker worm

Figure 1. Conficker worm

In recent years, aggressive computer worms have regained importance. Code Red was the first to raise a ruckus. This infection demonstrated how fast a type of self-program may propagate using today's internet infrastructure. Code Red took advantage of a buffer flow condition of the Microsoft Internet Information Server (IIS).

What Does a Computer Worm Do?

A computer worm can do many types of harmful activity depending on the algorithm that is based on. The worm can slow down the computer's performance when it is affected. Naturally, when the worm consumes your computers' physical memory, your other work will remain slow in operating. However, worms can crash the whole system completely if it is programmed to do so.

Worms are supposed to circulate and attack as many systems as possible. Worms frequently employ social engineering tactics. Malware developers do this by giving their dangerous files appealing names. The majority of these names have anything to do with sex, celebrities, or software piracy.

By transmitting malicious files to other users, we spread computer infections. They, like us, unwittingly accept and execute the attached file, resulting in a breach of your IT security.

How does it Work Computer Worms?

A computer worm, like any other virus, requires a person to start the transmission. Emails and web pages are the most common attack vectors of infection. The worm can be hidden in an infected email link or attachment or within the message, and it's frequently used in phishing schemes to disguise the infected item as something legitimate, such as a paper or spreadsheet.

Worms can also be installed if you visit a hacked webpage and click on a link that triggers the worm.

The worm begins creating duplicates of itself once it is implanted on your system. Some of these are set up to attack any device within the same local network automatically. Worms may also be capable of infecting any device that automatically connects to the host computer.

What are the Computer Worm Features?

1. Self-likeness

Worms acquire access to computers by exploiting known flaws in the target system. Because a worm's knowledge of vulnerabilities and systems is limited, the worm will constantly target the very same weakness for attacks. These cyber-attacks will be identical to those that have come before them.

2. Causal Connection

Worms must move between hosts in order to survive. Before such a worm could connect to a host, it must have received an incoming request from the host that originally placed the worm. A victim host is unable to infect additional hosts until it has been infected.

3. The Pattern of Destination Visits

Infecting a huge number of hosts is one of the architectural objectives for worms. In order to achieve this, worm-infected hosts attempt to connect to even more hosts' computers than non-infected ones would typically attempt. This increasing amount of attempted connections will eventually be noticed.

4. Consistency

Worm behavior is characterized by constant proliferation to acquire new hosts. This increased number of connections from many hosts should be noticeable.

What are the Different Types of Computer Worms?

A worm uses a lot of system resources, especially consuming network bandwidth, due to the nature of network replication, leading network servers to cease responding.

Here go five types of computer worms-

1. Worms on the Internet

The internet is utilized to find and influence other computers that are susceptible. These worms may readily infect computers that do not have antivirus software installed. Once the machines have been identified, they are infected, and the infection process begins all over again. If the system hasn't installed any, this is used to check for current updates and security measures.

2. Worms on File-Sharing Networks

When you download a file from an unnamed source, it may include a worm that tries to find a shared folder and damages other data. When another machine downloads a file out of the same connection, the worm detects it and replicates itself. The procedure is then repeated for each of the network's systems. Because these worms are multimedia or other extensions, people may simply download them believing they are a file extension.

3. Worms in Email

The worm uses the email box as a client or carrier. The message contains an affected link or file that, when clicked, installs the worm. The worm examines the infected system's email contacts and sends links to those computers, causing them to be destroyed as well. These worms feature multiple extensions, such as mp4 or video, to fool the user into thinking they are media extensions. These worms have a brief URL to open them rather than a download link.

4. Worms in Instant Messaging and Chat Rooms

These worms operate like email worms, stealing contacts from online forums and sending messages to them. The system gets infected once the recipient accepts the offer and clicks the message or link. The worms either have links to access web pages or download attachments. These worms don't work as well as other worms.

5. Worms on the Internet Relay Chat (IRC)

Internet Relay Chat had been a communications program that was popular at one time. IRC worms operated similarly to email and Instant Messaging worms, destroying computers in the IRC application's contact list.


Figure 2. IRC

It's critical to conduct a security check and detect a worm if you suspect your machine has one. Only the finest firewall and antivirus software will be able to assist you with this. To prevent vulnerabilities, the application must be updated on a regular basis. The use of unknown connections should be avoided at all costs.

What Do Computer Worms Harm?

While a computer worm's exact goal completely depends on its programming, in general, a worm will create duplicates of itself in order to propagate to new systems without being detected.

  • It may send an email using a contact list saved on the machine, and it can open Transmission Control Protocol (TCP) ports invisibly to compromise your network security.
  • Computer worms get so complicated with system data; it may easily bypass the firewalls and attack any other machine with which your computer communicates.
  • Computer worms may also harm end-users. Worms may alter or destroy files, lockout critical folders, or create performance problems for devices, depending on the payload - the program which executes the malware's goal. To steal data, some hackers employ worms, which may result in identity fraud. As a result, it is crucial to protect computers from computer worms.

Are There Any Helpful Computer Worms?

Worms are dangerous for computers. But, Welchia, also known as the Nachi worm, removes another worm named Blaster and fixes the loopholes that allowed Blaster to exist. While it has no malicious purpose, it has the effect of slowing down systems. It is a Nematode that is programmed to remove another virus.

Welchia searches in the 'dllcache' subfolder under the system directory for the tftpd.exe file. If it isn't found, it will additionally download that file to Wins as svchost.exe. This ensures that the Trivial File Transfer Protocol server is available to transmit and replicate itself to a new system.

However, welchia terminates 'msblast' and deletes the msblast.exe file. It looks in the registry to verify whether the Distributed Component Object Model (DCOM) vulnerability fix has been applied.

Welchia reboots the machine once the patch has been successfully deployed, completing the installation.

How does a Worm Infect a Computer?

The worm can affect a computer in many ways. Phishing, social engineering, file sharing, and security vulnerabilities are common. File-sharing services, email attachments, and visiting malicious links are all common ways for the worm to spread. Once acquired, the worm exploits a flaw in its target computer or deceives a user into running it. Many worms include a phishing mechanism to persuade victims to execute harmful programs.

Internet worms are often intended to take advantage of new security flaws and look for systems that haven't updated their software or operating systems.

Here are six ways-

  1. File-Sharing: Person-to-person (p2p) file-sharing could open the path to worm transmission if the sharing process doesn't have security essentials.
  2. Security vulnerabilities: If your computer has any security holes, an attacker could penetrate your system through that vulnerability. The worm could infect your computer in such a way.
  3. Network Security: When your network security doesn't comply with the standard requirement, your computer system could be an easy target for worm attacks.
  4. Phishing: The common way of spreading worms is the phishing attack. Often spear-phishing techniques are used to spread worms.
  5. External devices: External devices often bear worms that could affect your computer. Nowadays, the number has decreased because of the progress of cyber security tools and antivirus applications.
  6. Social networks: Your unaware use of social media could spread malware on your computer. Do not open any link or download any attachment without verifying the source of the sender.

How to Create a Computer Worm?

Creating a computer worm has different methods and purposes. The worm is usually designed for what purpose it will be used. Programming languages, interfaces, and attack surfaces vary in execution.

The first step is to determine the attack surface and plan for the tasks that the worm will do in the target computer system. Once you are done with these, write a program.

Commonly programming languages like C, C++, C#, and Java are used to code a worm. And finally, the exploitation depends on the vulnerabilities of the target computer.

How to Protect Your Computer from Worms?

If a worm gains access to your computer, the repercussions may be severe. The excellent news is that preventing computer worms comes down to a few common sense and wise practices that can be applied to worms in general. Make the following suggestions a part of your online activities if you haven't previously.

Some cybercriminals have become so good at hiding their harmful links that lingering over them won't help. There isn't a single viral video that is humorous enough to justify a virus infection. Skip the link and continue on your way.

2. Don't open an untrusted attachment

Make this a firm rule for yourself if it isn't already. Even if it's from someone you know, downloading an unexpected email attachment seldom results in anything positive. If that's the case, contact them to ensure that they are supposed to send it to you.

3. Use security software

Security applications, firewalls, and antivirus software can help your computer to remain worm-free. This security software detects viruses, worms, and malware and notifies to take action. Some applications automatically delete the worm from a computer system.

4. Use strong password

To infect different devices, several worms utilize default factory login credentials. Create complex passwords that are difficult to guess for your smartphone, computer, or any device, and don't use the identical password numerous times.

Strong passwords

Figure 3. Strong passwords

5. Use two-factor authentication

Using two-factor authentication or multi-factor authentication could save your sensitive data from being compromised by worm attacks. Initially, the attacker could get your login credential through a worm attack but 2FA and MFA could prevent you from data compromisation.

How to Avoid Computer Worms?

It takes advantage of the software application's security flaws and tries to get access in order to destroy sensitive data, corrupt files, and install malicious software remotely

These are some precautions you may take to keep your system, network, and personal information secure against computer worms.

1. Always keep your software up to date.

You must verify that all of your software is updated to the most recent version. The primary goal of downloading and installing the most recent version of the software is to keep your computer safe from viruses and worms.

Unpatched vulnerabilities in source code may exist in older versions of software, and when a new version is published, the new version typically contains patches for those kinds of security flaws.

2. Backup important files regularly

A data backup is a procedure for copying or archiving critical data files and documents in order to recover data if your computer becomes infected with the worm or malware.

When data has been lost due to computer viruses, worms, or cyber threats, it is the simplest method to restore your data from backup storage.

3. Scan your computer regularly

Frequently analyzing your system with an antivirus program is one of the simplest and most effective methods to avoid computer worms and viruses. After you've installed anti-virus software, do a full scan of your computer. If your anti-virus software has the ability to check files or directories automatically, turn it on at a convenient time.

4. Use a Firewall

Firewall monitors incoming and outgoing network traffic based on pre-set rules and security measures. It can protect your computer from worm attacks. A firewall blocks the traffic source if someone wants to push any malicious program or worm to the system. However, it also blocks suspicious internal traffic to protect data compromisation.

Zenarmor is one of the most powerful and cost effective next generation firewall software against malicious network traffic. It is widespread among small business and home networks.

How to Tell If Your Computer Has a Worm?

When your computer gets affected by worms it certainly does some unwanted activities. Slowing down the system, file not opening, running on low storage are some common issues that happen when the system is under a worm attack.

Some worms, such as the Morris Worm, may use up so much of a computer's resources that there isn't much available for regular operations. It's possible that a computer worm is to blame if your computer becomes slow or sluggish or even crashes.

According to the earlier discussions, worms can replicate themselves automatically. That means new worms are consuming storage to be available at the system. If you think your computer storage is way higher than it should be, it could be worms that are taking space.

What is the Difference Between Computer Virus and Computer Worms?

A computer virus is harmful code-based software that may spread from one device to another. When your computer gets infected, it changes the way it works, may damage your data, or prevent it from functioning entirely.

The distinction between such a virus and a computer worm would be that viruses need human activity to activate and must multiply in a host system. In other words, unless you run a virus, it will not damage your computer.

  • A computer virus attaches itself to the operating system and does harmful activity in the system to steal or damage data. On the other hand, computer worms do not attach to the operating system. Worms work in the file system.
  • Viruses need human action to set their tasks after affecting a computer system. For example, an attacker can push a virus to your system but it will not send any information until the attacker commands it to do so.

In contrast, worms can replicate and spread without human interaction. It can also send information if it is designed to do that.

  • In contrast to damages, a virus attacks a specific computer first and does harm to the computer system. Later it could be spread to other computers. But the computer worm harms networks and spreads among the connected devices.
  • Computer viruses spread slowly compared to the computer worm. Worms spread rapidly.
  • Viruses are complex programs that is hard to remove from the computer. Often antivirus finds it hard to detect and remove viruses from a computer.

But, worms are comparatively easy to detect and delete. However, there are some worms that remain almost hidden from security checks. They are hard to find and remove.

  • The virus can affect other files and programs making them unable to access but worms do not affect other files. Worms occupy physical memory and make the system slow.