Our computer experts sort them out
Keeping your computer safe from viruses is essential to prevent hackers gaining access to your system. Delia Gill, Director of Quay Corporate Limited, offers tips to help you keep your computer safe from viruses and other malicious software (malware). She explains what malware is, what it does, how to prevent it attacking your computer and how it can be removed if your computer is attacked.
Tips to keep your PC safe
- Make sure you keep your computer up to date with both Windows updates and antivirus updates – Windows updates are just as important as updating your virus definitions.
- Keep the firmware (i.e. the software on the firewall) up to date.
- Be wary who you let on your computer – you might be cautious but somebody else might not be.
Why software updates are critical
All software is binary (i.e. code 00100111000011100000). It is created by humans and therefore is fallible and full of, for lack of a better word, “bugs.” Software updates can be an irritation (and sometimes time consuming as you reboot your PC). BUT they are incredibly important. Not only do they fix errors in code and improve usability, but they also correct potential “holes” or vulnerabilities in the software that can be targeted by hackers. A classic example of this is the Conficker virus, picked up in November 2008. Because some people did not pay attention to the Microsoft updates alerts, their machines became infected and spread the virus – yet a simple Windows update would have stopped it. It is believed that more than 3 million computers are still infected. For more information see http://en.wikipedia.org/wiki/Conficker
Microsoft does flood us with updates and as a result we can get a bit blasé about them. To avoid being hacked, it’s best to accept that about every fortnight your computer will update and reboot. You can have a look beforehand and dismiss what you don’t want. You must allow any that are marked important or recommended. Whatever you do, don’t interrupt the update process once it has started – PCs don’t like half an update and they tend to get very upset. A good overview article on Microsoft updates is http://blogs.computerworld.com/14777/which_windows_updates_should_i_install
A problem with software updates is that sometimes the updates can cause issues with other pieces of software. As most PCs are individual, especially in a small business, it’s impossible to get everything accounted for. 99% of the time they get it right. But that 1% can be a pain in the butt! Ask us for help with this one.
What is malicious code or malware?
Malware is malicious code – for the sake of expedience I am going to use the common word “virus.” Over the last 10 years viruses have changed from people showing off their abilities to being about money and control. The most common form of virus that we encounter these days is one that has been what we term invited. A well-meaning PC user is surfing the net when a little message pops up saying that their computer is infected – click here to fix – the user then clicks yes and voilà, something nasty is now installed on the machine. Nine times out of ten the innocent PC user won’t even know it’s there because it pretends to be valid, even helpful, software.
Malware is so prevalent in the IT industry that results from Symantec, published in 2008, suggest that the release rate of malicious code and other unwanted programs may be exceeding that of legitimate software applications. And, according to internet security firm
F-Secure, “As much malware was produced in 2007 as in the previous 20 years altogether.”
Types of malware
The term malware includes:
Still other nasties just want to kill off your machine. As for spam – remember that some spam has malware attached to it.
How viruses attack your PC
A common type of virus, the Trojan horse, first attacks the installed antivirus program on the machine. It hides in the background, even leaving all the antivirus icons on the computer, so it looks like the antivirus is still working. BUT really the virus (actually the person controlling the virus, known as a hacker) has control of the machine. They can then do a number of things and it depends what their intent is.
How viruses spread
A true virus or malware can be spread in many ways, including email and webpages that have malicious code “injected” into them (but this can also occur by inserting an infected memory key). The virus or malware can then do such things as and spread itself out again from there. We[SFM1] saw a number of these sorts of thing years ago – there was always that big one that went round the world blocking up the internet, servers etc and just generally wreaking havoc. These days we actually don’t see as many of these any more – the little men in the dark rooms have become more sophisticated.
What a hacker can do to your computer
The hacker now has the ability to perform tasks using your computer system – and that’s scary! These operations can include:
- Use of the machine as part of a botnet in order to perform denial-of-service attacks
- Data theft (e.g., passwords, security codes, credit card information)
- Installation of software (including other malware)
- Downloading of files
- Uploading of files
- Keystroke logging
- Viewing the user’s screen
Botnet
This is the term for a group of computers (a typical botnet can consist of 50,000 computers) taken over or ‘owned’ by a hacker. Botnets can then be hired out by the hacker.
Denial of service attack
A denial of service attack is where the virus/malware gets the host PC to access a server/website on the internet. Now this does not sound like much, but if you have 50,000 computers doing the same thing – the poor server on the other end that hosts the website generally will not cope with the load and fail to deliver its serves to legitimate requests.
Downloading of files
Files can be removed from your system.
Uploading of files
The hacker puts files of their own on to your system.
Keystroke logging
This captures every key you hit (useful for stealing passwords, etc)
Firewalls
It is really good to have a firewall (in the case of businesses with servers they are essential). BUT remember that no firewall (or antivirus software) can stop some malicious code if you accept it. Do not, for example, click ‘yes’ to install antivirus software when you already have some, or when it’s something that you have never heard of! I have lost count of the times I have heard someone say “But, but, but … I have a firewall!”
Removing malware from your computer
To remove malware we have to remove the hard drive and boot it up in a “clean” machine, or boot the PC up from a CD in order to prevent the virus activating during the normal boot process. As the virus can replace or remove critical system files, it can mean that a reload of the entire system is required. Often to clear out a machine we will have to back up the user’s personal files and email, and then completely reload the system. This becomes very serious when you are talking about a server.
Summary
Remember that your PC is a business tool and it must be treated as such. Don’t put games on it or let people use it who might download things like music on to it. Once people do that, your PC is no longer a business tool. Look after your PC by keeping them safe from viruses and you’ll be free to concentrate on your work and your business.
A shorter version of this article was published by Her magazine in March 2009, where there were also interesting articles on the bugs of the information era, spam, social media, and greening your gadgets, as well as a quiz on techno-babble. Hermagazine.co.nz has more information about the magazine and the Her Business Network.
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