How to maintain and speed up your computer - an out of the box guide (computer surge blues), part 3

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Malware- what it is, how to face it

What is is
In the computer world there are good and bad guys just like in yours and, just such as yours, there are several kinds of bad guys. When we talk generally about them, we use the term malware, which is short for malicious software. This term is referred to bad programs, conceived to harm me in different ways. Before we talk about that, I have to give you a heads up: this distinction isn't so clear-cut in the real world. Just as a bad guy can be a thief and a con artist at the same time, a malware can be hybrid and it's sometimes hard to tell what it exactly is.

 

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A  computer virus is so called because it behaves just about like a biological virus; when executed (double-clicking an .exe file or a file disguising an .exe file), it replicates by copying itself into other computer programs, files, or the boot sector of the hard drive and spreading like an infection. That's why, when these bad guys' attack is successful, you say that I'm "infected".
A worm tries to transmit itself over a network to infect other computers or it sends copies of itself to all of your email contacts. When a friend of yours calls you or emails you about an email you've sent to him and you're sure you didn't do it, heads up: it means I've been compromised!
Other kinds of malware don't replicate themselves, but rather try to hide as deep as possible into my operating system to get hold of me and steal information from you (or sometimes simply to prank you /scare you to death/blackmail you, depending on what kind of hacker you're faced with). This is the case for Trojan horses, backdoors, rootkits and key-loggers (sometimes they're generally called spyware -spying software- because they illegally spy what you do with me).

Trojan horses are bad guys disguised as good ones, just like the famous wooden horse used by the Greeks to sneak into Troy undetected. They can look like legitimate programs or like an attractive file that tells you "click me, click me!" such as a famous woman's sexy pic (e.g. Anna Kournikova Trojan horse) and they hide both into files you download from the web and into email attachments. The only way they can harm me is by clicking them, so please don't! If you fell for it, you've just installed the client component of the Trojan horse. The attacker controls the server component and, through that, he can command me and make me do whatever he likes. He can make me misbehave and prank you, such as opening and closing the DVD drive, popping up text, audio and video messages on screen, inverting the mouse button, redirect ports, etc. Please don't let this happen, I feel bad later, just like you do when you have a hangover after a bad night.
Backdoors are vulnerabilities in the program code used by hackers to gain illegal access to me. Once bad guys find a vulnerability that can be exploited, they use it opening up a "door", i.e. accessing me illegally. Then they make me sick, so they can do what they want without being held responsible for that.
Rootkits are a stealthy type of software, usually malicious, that hides into my operating system, making certain procesesses or programs invisible to the user and to some antivirus software and running them undetected every time you power me on. They are given administrative rights so they can do whatever they want with me (root user in Unix systems is the administrator user account, who's almighty because he has full access to me and my files). These are among the most dangerous bad guys ever; they often keep a low profile and you don't realize they hide inside me till you scan my hard drive with specific software.
(Software) key-loggers are sneaky bad guys intercepting and logging into a file any key you press on your keyboard. This log file is then emailed or accessed from the web by the attacker, who steals your passwords, your banking information or your work emails.

What can be done to face and prevent malware

Prevention

1. Install an antivirus software and keep it updated: These buddies are essentially our cops in the computer world, they're designed to detect and remove malware in general, but mostly viruses and worms. They can be commercial (you have to pay for their services) or free. I won't tell you which one is the best, it's up to you what you choose but I can give you an advice; always choose only solid, well-known antivirus software and check for online reviews, otherwise you risk to install a so-called hoax virus (a virus disguised as an antivirus program). Hoax viruses fill your screen with annoying pop-up windows alerting you that infected files have been detected and urging you into buying the full version to get rid of them. Don't do it, it's a psychological scam and I wish I could yell at you in this case: "I'm alright, this crook is ripping you off!" Any solution you choose, make sure that my antivirus software gets constantly updated. Why's that? Just like diseases, new viruses get created every day but my buddy antivirus can protect me against the new threats only if you update its definitions (his wanted list). You can risk otherwise he checks a file and thinks it's OK while it's infected by a new virus he didn't know of.
2. Install an antispyware software and keep it updated: Now you'll think, why a specific software for it, isn't antivirus enough? Well, not all antivirus programs do an excellent job at detecting bad guys, just like there are better cops than others. Some antivirus programs detect almost everything while other ones can fail to detect some specific malware. However, a specific anti-spyware software should be able to detect all kinds of spyware (at least in most cases).
3. Don't download files or open email attachments coming from sources you don't know;
4. Check if you're using the latest version of your browser and, if you're really scared by virus, utilize a user account with limited permissions to surf the web, so you won't be allowed to install anything.
5. When you end up on a website you don't know (especially if it starts opening up a bunch of pop-up windows and/or looks anyway suspicious) close it immediately, delete browser cache and cookies and scan my hard drive. Sometimes I can be infected by a script or a malicious cookie simply by viewing a website.
6. When you receive suspicious emails full of grammatical errors or allegedly coming from your bank, never click the link contained in the email body because it may lead to a malicious website that can look like a legitimate one (such as your bank website) but it's only designed to steal your information. This kind of cyber attack is called phishing.

 Malware removal

1. If I've been compromised, access Safe Mode pressing F8 after Windows startup and scan my hard drive. This way you'll get rid of the bad guys more easily and quickly, as they are inactive when you boot me in Safe Mode (they don't get loaded by my operating system in that case). When you've done, reboot me to go back to normal mode.
2. Scan my hard drive using several programs. This is safer because some program does a better job in detecting malware and, if you use more than one of them, it's harder for a bad guy to hide. Important rule: Do not install more than one antivirus program to monitor your computer real time in background. Otherwise these buddies conflict and each one of them wants to have his way. You can use an installed antivirus program and an online scanner at the same time or antivirus program and an anti-spyware program simultaneously, though.
3. Check on me with an online antivirus scanner. Don't trust your resident antivirus program because bad guys could have altered it so that it doesn't function at all or it doesn't detect certain files. Utilize an online scanner actually capable to remove infected files (Nod32, BitDefender, McAfee, for example).

Wrap-up 

There can be many reasons why I don't behave myself, but it's not always on me. I hope now you understand better why this can happen and stop blaming me and yelling at me all the time.
As you could see, your habits can impact my performance; I've showed you how you can rethink your habits and make me quicker so you're happy.
I explained you also why I can get sick and what you can do both to prevent it and to heal me when this happens. I hope you've enjoyed this trip.


See you in the coming posts!


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