A computer worm is a piece of malware whose primary function is self-replication. It infects other computers without any human intervention, and it remains active on those infected systems.
Computers can be infected with worms in one of two ways: Via email or by downloading infected files from the Internet. Worms also use social engineering techniques to trick users into opening an infected file.
A computer worm is similar in design to a computer virus, but there are some crucial differences between the two. The main objective of the Computer worm is to eat the system resources, whereas that of the Computer virus is to modify the information.
For example, the Blaster Worm spread like wildfire in the mid-2000s thanks to a vulnerable, open network port on Windows computers.
On the other hand, the Shamoon virus was highly destructive, impacting all computers in a specific network having 32-bit NT kernel versions of Windows.
What is the Difference between a Worm and a Virus?
Viruses are self-contained computer programs, whereas worms leave parts of themselves on each newly infected computer. Computer worms rely on social engineering techniques to remotely infect people’s computers and do more damage than a virus due to their ability to get around security features quickly.
A virus is contained and does not interact with other files without human intervention. In contrast, trojan horses cannot replicate themselves but depend on the user running them to install some malware or spyware. This means that they do not disable your defenses as much as a worm would have the potential to do.
What Type of Computer Worms exists?
There are five common types of computer worms :
Computer worms also plague popular websites with weak security, just like they do to computer networks. Internet worms can spread to other computers by replicating themselves and copying onto connected systems.
So, if you happen to access the infected site, it will get into your pc and then distribute itself to your other system files.
Email worms spread themselves by attaching themselves to an email as an infectious executable file. These send themselves as an attachment to all the contacts in the user’s email address book.
As soon as a user opens the attachment, a copy of the worm executes itself and starts replicating itself repeatedly until all available resources are consumed.
The worm copies itself into shared folders on the affected computer. When another user accesses that shared folder, they infect their computer with a copy of the original worm.
These malicious programs are disguised as media files with dual extensions like instant messaging worms.
Cryptoworms utilize strong encryption to gain access to a computer and can only be removed using cryptographic tools. They demand payment in exchange for a key to decrypt their files while decreasing your security.
Instant Messaging Worms
Instant messaging worms use programmed social engineering techniques to find potential victims.
The worm contacts a chat server and sends itself as an infected file attachment in the body of an instant message to everyone in the user’s contact list unless it finds any security-related information during its survey.
They often come with a short, deceiving message that tricks the recipient into thinking their friend was the one sending it. They may state “LOL” or say something similar to entice viewers to click on them.
If the worm has not replicated onto their computer, users can solve this problem by changing their password.
Recent Worm Attacks
In the most recent ransomware assault on a large US healthcare provider, 1.4 million person medical and financial records were potentially compromised earlier this year.
How do I know if my PC has been Infected with a Worm?
Specific symptoms might indicate that your PC is infected with a worm, such as:
Unusual Pop-up Windows – These are usually fake warnings to say that you have been infected with Virus. The usual call to action suggested is to Press on OK or a link. Remember, Windows Defender will never pop up like this!
Inability to connect to the Internet – If your computer cannot connect you to either an IP, website or web page, there might be worms on your machine.
Additional Items being installed – One symptom of a worm infecting your system is installing several random items onto your PC. These will often be shortcuts and pop-up ads that are unrelated to the software you were downloading. This is common for installers who claim they support an advertised application but don’t install anything. They add extra junk and advertisements onto your system!
Unusual messages before or after logging into your accounts such as Facebook, Twitter, or your ISP (Internet Service Provider) – Worms can make you visit a website with malicious content, and it might cause warnings from your browser.
Look for new Open ports on your computer – Sometimes, worms install port forwarding to access specific programs. This won’t happen if the worm only replicates itself without the intention of stealing data!
Unexplained connectivity problems and network disconnections.
Lagging performance even if you have enough disk space and memory available.
A mobile code-red worm is a computer virus that targets Microsoft Windows and its derivatives and requires no user action beyond normal surfing. It was one of the most rapidly spreading worms in history, infecting over 359,000 computers on the Internet in less than fifteen minutes, causing significant issues for major corporations like Yahoo!, CNN, or eBay.
Now that we know about worms let’s look at Trojan.
How is a Worm Different from a Trojan?
Unlike Viruses, a trojan or Trojan Horse, on the other hand, is malware that gets into your computer through software – usually via email attachment or some form of social engineering.
This means they get past security measures without you noticing anything amiss at all (until after they have done their damage). They often act as backdoors, allowing an attacker to take complete control of the infected device remotely.
Consider Trojan horses, worms, and viruses as malicious software.
So, here are the quick differences between worms and trojans.
Not Self-replicating but captures important system information
Can be controlled by hackers remotely with unauthorized access
Like worms, it can also be controlled by hackers remotely
Objective is to degrade the system performance
Used as a tool to steal vital information from the computer
How to find Trojan Horse on my Computer?
Trojan horses often come with a package that installs additional advertising software. One key sign of having a Trojan horse is to look for the following items:
Unusual, unexpected ads that are different from your regular ads and don’t go away when you close them
Modified homepage – The homepage in your browser might show something different than what it usually does.
Unexpected changes on your desktop settings – Your desktop wallpaper or screensaver might be changed suddenly. There are also cases where tiny, hidden icons that you cannot find because they blend into the background or only show up when the system starts.
Unexpected changes on the “allowed” programs you can download – You might notice there are programs you cannot download anymore or some that you can’t uninstall but show up as installed in your system.
Unusual messages from system security software – for example, if a virus protection program shuts down or warns about suspicious activity
Your hard disk suddenly starts getting full – the system might be writing to your hard drive even though you don’t have a lot of files.
Redirected to unsafe websites by changing settings in browsers and installing malicious extensions and plug-ins.
There are seven different types of dangerous trojan horse viruses that can infect your computer.
A backdoor Trojan is a type of malware that gives the author remote control over your computer.
This includes everything from sending and receiving files and launching programs on their behalf to accessing sensitive information like passwords or credit card numbers stored inside documents that can be deleted without being ever noticed by you.
A rootkit is a computer program designed to provide continued privileged access while actively hiding its presence.
This illicit software may be installed on your system and remain undetected for months or even years before you are made aware that something has gone wrong with one of the many functions it provides – such as Internet connectivity!
A trojan-downloader is a type of malicious software that installs itself on the system and waits for an Internet connection to connect to a remote server or website to download additional programs (usually malware).
A Banker Trojan is a malicious code that aims to steal sensitive or valuable information stored or handled through online bank systems.
Ransomware attacks are most often carried out via a Trojan, which infiltrates the system by, for example, tricking people into opening an attachment from a Phishing email or exploiting a network service vulnerability.
A Trojan-Spy can access information from your computer, track activities such as keylogging and monitoring program execution on the computer, as well as steal data from files saved on the machine.
Denial of Service(DoS) Attack Trojan
A distributed Denial of Service or DDoS attack is an attempt to bring down a machine or network, preventing it from being used by its intended users.
The objective of a DoS assault is to disrupt regular traffic or send data that leads to a crash.
An exploit is a tool that takes advantage of a software or operating system’s vulnerability or loophole. Exploit kits, which are most often found on hacked websites, employ exploits.
The kit quietly explores the computer or device of an unsuspecting user while they view the page.
Fake AV(antivirus) Trojan
Fake AV programs disguise as antivirus software and perform all sorts of activities like scanning the system, displaying security-related alert messages, and offering up security updates.
So, in conclusion, when you’re talking about computer viruses, it’s essential to know the difference between worms and trojans.
A worm is a virus that spreads from device to device by replicating itself, just like those awful messages that show up on your email or social media feed.
In contrast, a trojan is a type of Virus that enters your computer through software and can cause problems with your data and other devices.