Computer Virus
A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code.[1] When this replication succeeds, the affected areas are then said to be "infected" with a computer virus.
A computer virus is a malicious program that self-replicates by copying itself to another program. In other words, the computer virus spreads by itself into other executable code or documents. The purpose of creating a computer virus is to infect vulnerable systems, gain admin control and steal user sensitive data. Hackers design computer viruses with malicious intent and prey on online users by tricking them.
The term 'computer virus' was first formally defined by Fred Cohen in 1983. Computer viruses never occur naturally. They are always induced by people. Once created and released, however, their diffusion is not directly under human control. After entering a computer, a virus attaches itself to another program in such a way that execution of the host program triggers the action of the virus simultaneously. It can self-replicate, inserting itself onto other programs or files, infecting them in the process. Not all computer viruses are destructive though.
The terms “virus” and “malware” are often used interchangeably, but they’re not the same thing. While a computer virus is a type of malware, not all malware are computer viruses.
Not every piece of software that attacks your PC is a virus. Computer viruses are just one kind of malware (malicious soft-ware). Here are some of the other, most common kinds:
Trojans: like the ancient wooden horse full of attackers it takes its name from, this malware pretends to be harmless legitimate software, or comes embedded in it, in order to trick the user and open up the gates for other malware to infect a PC.
Spyware: with examples such as keyloggers, this kind of malware is designed to spy on users, save their passwords, credit card details, other personal data and online behavior patterns, and send them off to whoever programmed it.
Worms: this malware type targets entire networks of devices, hopping from PC to PC.
Ransomware: this malware variety hijacks files (and sometimes an entire hard drive), encrypts them, and demands money from its victim in exchange for a decryption key (which may or may not work, but it probably won’t).
Adware: this exceedingly irritating kind of malware floods victims with unwanted ads, and opens up vulnerable security spots for other malware to wiggle its way in.
A computer virus works in much the same way:
A computer virus requires a host program.
A computer virus requires user action to transmit from one system to another.
A computer virus attaches bits of its own malicious code to other files or replaces files outright with copies of itself.
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. Some of the most common viruses are,
Boot Sector Virus
Direct Action Virus
Resident Virus
Multipartite Virus
Polymorphic Virus
Overwrite Virus
Spacefiller Virus
Computer virus symptoms
How can you tell if a virus has slipped past your defenses? With some exceptions, like ransomware, viruses are not keen to alert you that they've compromised your computer. Just as a biological virus wants to keep its host alive so it can continue to use it as a vehicle to reproduce and spread, so too does a computer virus attempt to do its damage in the background while your computer still limps along. But there are ways to tell that you've been infected. Norton has a good list; symptoms include:
Unusually slow performance
Frequent crashes
Unknown or unfamiliar programs that start up when you turn on your computer
Mass emails being sent from your email account
Changes to your homepage or passwords
Can your computer become infected with a virus via email?
Your computer can become infected with a virus via email, but only if you open attachments within a spam email or click on the links contained in them.
Simply receiving a spam email will not infect your computer. Just mark these as spam or junk and ensure they are deleted. Most email providers will automate this (Gmail for example) but if any slip through the net, just mark them as spam yourself and don’t open them.
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.
Best Antivirus Software Secure your personal data
Installing antivirus protection on your computer means your family will never compromise data or security. Protect your computer from online threats by selecting the right software for your needs.
- Bitdefender Antivirus Plus
- Norton AntiVirus Plus
- Kaspersky Anti-Virus
- F-Secure Antivirus SAFE
- ESET NOD32 Antivirus
- Trend Micro Antivirus+ Security
- Webroot SecureAnywhere AntiVirus
- G-Data Antivirus
- Comodo Windows Antivirus
- Panda Essential
- Avira Antivirus
No comments:
Post a Comment