What is a computer virus?
Think of a biological virus – the kind that makes you sick. It’s persistently nasty, keeps you from functioning normally, and often requires something powerful to get rid of it. A computer virus is very similar. Designed to replicate relentlessly, computer viruses infect your programs and files, alter the way your computer operates or stop it from working altogether.
How does a computer virus find me?
Even if you’re careful, you can pick up computer viruses through normal Web activities like:
Sharing music, files, or photos with other users
Visiting an infected website
Opening spam email or an email attachment
Downloading free games, toolbars, media players and other system utilities
Installing mainstream software applications without thoroughly reading license agreements
What does a computer virus do?
Some computer viruses are programmed to harm your computer by damaging programs, deleting files, or reformatting the hard drive. Others simply replicate themselves or flood a network with traffic, making it impossible to perform any internet activity. Even less harmful computer viruses can significantly disrupt your system’s performance, sapping computer memory and causing frequent computer crashes.
What are the symptoms of a computer virus?
- Your computer may be infected if you recognize any of these malware symptoms:
- Slow computer performance
- Erratic computer behavior
- Unexplained data loss
- Frequent computer crashes
- How to protect against computer viruses
- When you arm yourself with information and resources, you’re wiser about computer security threats and less vulnerable to threat tactics. Take these steps to safeguard your PC with the best computer virus protection:
- Use antivirus protection and a firewall
- Get antispyware software
- Always keep your antivirus protection and antispyware software up-to-date
- Update your operating system regularly
- Increase your browser security settings
- Avoid questionable Web sites
- Only download software from sites you trust.
- Carefully evaluate free software and file-sharing applications before downloading them.
- Don't open messages from unknown senders
- Immediately delete messages you suspect to be spam
An unprotected computer is like an open door for computer viruses. Firewalls monitor Internet traffic in and out of your computer and hide your PC from online scammers looking for easy targets. Products like Webroot Internet Security Complete and Webroot Antivirus provide complete protection from the two most dangerous threats on the Internet – spyware and computer viruses. They thwart threats before they can enter your computer, stand guard at every possible entrance of your computer and fend off any computer virus that tries to open, even the most damaging and devious strains.
While free antivirus downloads are available, they just can't offer the computer virus help you need to keep up with the continuous onslaught of new strains. Previously undetected forms of polymorphic malware can often do the most damage, so it’s critical to have up-to-the-minute, guaranteed antivirus protection.
What are the risks of a computer virus?
- Viruses and spyware can cause very serious consequences including:
- Identity theft.
- Fraud.
- Deletion, theft and corruption of data.
- A slow or unusable computer.
Are viruses bad for computers?
A computer virus is malware attached to another program (such as a document), which can replicate and spread after an initial execution on a target system where human interaction is required. Many viruses are harmful and can destroy data, slow down system resources, and log keystrokes.
Types of Computer Viruses
A computer virus is one type of malware that inserts its virus code to multiply itself by altering the programs and applications. The computer gets infected through the replication of malicious code. Computer viruses come in different forms to infect the system in different ways. Find some of the most common type of computer viruses here,
- Boot Sector Virus
- Direct Action Virus
- Resident Virus
- Multipartite Virus
- Polymorphic Virus
- Overwrite Virus
- Spacefiller Virus
Boot Sector Virus – This type of virus infects the master boot record and it is challenging and a complex task to remove this virus and often requires the system to be formatted. Mostly it spreads through removable media.
Direct Action Virus – This is also called non-resident virus, it gets installed or stays hidden in the computer memory. It stays attached to the specific type of files that it infect. It does not affect the user experience and system’s performance.
Resident Virus – Unlike direct action viruses, resident viruses get installed on the computer. It is difficult to identify the virus and it is even difficult to remove a resident virus.
Multipartite Virus – This type of virus spreads through multiple ways. It infects both the boot sector and executable files at the same time.
Polymorphic Virus – These type of viruses are difficult to identify with a traditional anti-virus program. This is because the polymorphic viruses alters its signature pattern whenever it replicates.
Overwrite Virus – This type of virus deletes all the files that it infects. The only possible mechanism to remove is to delete the infected files and the end-user has to lose all the contents in it. Identifying the overwrite virus is difficult as it spreads through emails.
Spacefiller Virus – This is also called “Cavity Viruses”. This is called so as they fill up the empty spaces between the code and hence does not cause any damage to the file.
#File infectors:
Few file infector viruses come attached with program files, such as .com or .exe files. Some file infector viruses infect any program for which execution is requested, including .sys, .ovl, .prg, and .mnu files. Consequently, when the particular program is loaded, the virus is also loaded.
Besides these, the other file infector viruses come as a completely included program or script sent in email attachments.
#Macro viruses:
As the name suggests, the macro viruses particularly target macro language commands in applications like Microsoft Word. The same is implied on other programs too.
In MS Word, the macros are keystrokes that are embedded in the documents or saved sequences for commands. The macro viruses are designed to add their malicious code to the genuine macro sequences in a Word file. However, as the years went by, Microsoft Word witnessed disabling of macros by default in more recent versions. Thus, the cybercriminals started to use social engineering schemes to target users. In the process, they trick the user and enable macros to launch the virus.
Since macro viruses are making a come back in the recent years, Microsoft quickly retaliated by adding a new feature in Office 2016. The feature enables security managers to selectively enable macro use. As a matter of fact, it can be enabled for trusted workflows and blocked if required across the organization.
#Overwrite Viruses:
The virus design purpose tends to vary and Overwrite Viruses are predominantly designed to destroy a file or application’s data. As the name says it all, the virus after attacking the computer starts overwriting files with its own code. Not to be taken lightly, these viruses are more capable of targeting specific files or applications or systematically overwrite all files on an infected device.
On the flipside, the overwrite virus is capable of installing a new code in the files or applications which programs them to spread the virus to additional files, applications, and systems.
#Polymorphic Viruses:
More and more cybercriminals are depending on the polymorphic virus. It is a malware type which has the ability to change or mutate its underlying code without changing its basic functions or features. This helps the virus on a computer or network to evade detection from many antimalware and threat detection products.
Since virus removal programs depend on identifying signatures of malware, these viruses are carefully designed to escape detection and identification. When a security software detects a polymorphic virus, the virus modifies itself thereby, it is no longer detectable using the previous signature.
#Resident Viruses:
The Resident virus implants itself in the memory of a computer. Basically, the original virus program is not required to infect new files or applications. Even when the original virus is deleted, the version stored in memory can be activated. This happens when the computer OS loads certain applications or functions. The resident viruses are troublesome due to the reason they can run unnoticed by antivirus and antimalware software by hiding in the system’s RAM.
#Rootkit Viruses:
The rootkit virus is a malware type which secretly installs an illegal rootkit on an infected system. This opens the door for attackers and gives them full control of the system. The attacker will be able to fundamentally modify or disable functions and programs. Like other sophisticated viruses, the rootkit virus is also created to bypass antivirus software. The latest versions of major antivirus and antimalware programs include rootkit scanning.
#System or Boot-record Infectors:
The Boot-record Infectors infect executable code found in specific system areas on a disk. As the name implies, they attach to the USB thumb drives and DOS boot sector on diskettes or the Master Boot Record on hard disks. Boot viruses are no more common these days as the latest devices rely less on physical storage media.
How To Avoid Email Viruses And Worms
Here are some simple rules you can follow to avoid being infected by viruses through email.
How To Be Safe From Email Viruses And Worms
Here are some simple rules you can follow to avoid being infected by viruses through email.
Do’s
1. Use a professional, email service such as Runbox. Subscription services provide higher levels of security and support.
2. Make sure that your Runbox virus filter is activated.
3. Use the Webmail interface at www.runbox.com to read your email, or don’t download all your email to an email client unseen. Screen your email first, and delete suspicious-looking and unwanted messages before downloading the legitimate email to your local email client.
4. Make sure your computer has updated anti-virus software running locally. Automatic updates are essential for effective virus protection. Combined with server-side scanning, you now have two layers of security.
5. Disable message preview in your email client, especially on Windows platforms. Otherwise, malicious programs attached to incoming messages may execute automatically and infect your computer.
6. Ignore or delete messages with attachments appearing to be sent from official Runbox email addresses. Runbox rarely sends email to our users, aside from replies to inquiries and payment reminders. We practically never send an email with attachments to users.
7. Take caution when opening graphics and media attachments, as viruses can be disguised as such files.
8. Maintain several independent email accounts. If a virus infects your only business email address, you’ll be in trouble. Also, keep backups of your most important email and files separately.
9. If any valid message headers of a virus-email indicate what server the message was sent from, contact the service in question and file a formal complaint.
Don’ts
1. Do not open an email attachment unless you were expecting it and know whom it’s from.
2. Do not open any unsolicited executable files, documents, spreadsheets, etc.
3. Avoid downloading executable or documents from the internet, as these are often used to spread viruses.
4. Never open files with a double file extension, e.g. filename.txt.vbs. This is a typical sign of a virus program.
5. Do not send or forward any files that you haven’t virus-checked first.
6. Viruses and spam
7. Virus-makers and spammers often cooperate in devious schemes to send as much spam as possible as efficiently as possible. They create viruses that infect vulnerable computers around the world and turn them into spam-generating “robots”. The infected computers then send massive amounts of spam, unbeknownst to the computer owner.
Such virus-generated email is often forged to appear to be sent from legitimate addresses collected from address books on infected computers. The viruses also use such data, combined with lists of common (user) names, to send spam to huge numbers of recipients. Many of those messages will be returned as undeliverable, and arrive in innocent and unknowing email users’ Inboxes. If this happens to you, use the trainable spam filter to catch those messages.
How To Get Rid Of Computer Virus
Never the neglect to take action on a computer virus residing in your system. There are chances that you might end up losing important files, programs, and folders. In some cases, the virus damages the system hardware too. Thereby, it becomes mandatory to have an effective anti-virus software installed on your computer to steer clear of all such threats.
Signs of Virus Infection
It is vital for any computer user to be aware of these warning signs –
• Slower system performance
• Pop-ups bombarding the screen
• Programs running on their own
• Files multiplying/duplicating on their own
• New files or programs in the computer
• Files, folders or programs getting deleted or corrupted
• The sound of a hard drive
If you come across any of these above-mentioned signs then there are chances that your computer is infected by a virus or malware. Not to delay, immediately stop all the commands and download an antivirus software. If you are unsure what to do, get the assistance of an authorized computer personnel. If you are confident enough, start investigating on your own by following the below mentioned step-by-step procedures.
#Safe Mode
Boot the system and press F8 for Advanced Boot Options menu. Select Safe Mode with Networking and press Enter. You might need to keep repeatedly pressing to get on to the screen.
Working on the Safe Mode helps handle nefarious files as they’re not actually running or active. Last but not the least the internet spreads the infection, so remove the connection.
#Delete Temporary Files
In order to free the disk space, delete temporary files before starting to run the virus scan. This approach helps speed up the virus scanning process. The Disk Cleanup tool helps in deleting your temporary files on the computer.
Here is how you got to go about accomplishing it – Start menu then select All Programs, now you click on Accessories, System Tools, and then click Disk Cleanup.
#Download Virus/Malware Scanner
If you are under the impression that a virus scanner cleanups the bad stuff from your computer then sadly, that’s not true! It helps in eliminating standard infections and not sufficient to remove the latest harmful infections. The virus/malware scanner helps to narrow down on the issue, so, download it now. In order to better protect go for a real-time anti-virus program, since it automatically keeps checking in the background for viruses.
