Do you REALLY need to know the difference between malware types?

Explaining Malware Types is Hard To Do

One of the stranger perils of being a technical writer involves being ambushed at odd moments by people demanding on-the-spot explanations of complex technical concepts.  I was out on the town one night and somehow found myself having to explain to a not-too-tech-savvy friend how to differentiate between a virus, a trojan and a worm.

After patiently listening to a lengthy, rambling answer, my friend thought it over for a minute and then asked, “So, why should I care? Why is this important to me? Do I really need to know the difference between different types of malwares?

My automatic reaction was to say, “Of course you need to!” – but to my surprise,  I couldn’t coherently express why I felt that way (though to be fair,  I was having trouble thinking clearly about anything that night).

Thinking it over in the sober light of day,  I realized that he’d actually asked a pretty good question. For most computer users, the difference between malware types is academic and irrelevant – at least,  right up until their computer gets infected. If everything’s working just fine, why in the world should they be able to distinguish between an exploit and a backdoor?

A Technical Person’s Answer

To get a expert’s opinion on this,  I relayed my friend’s question to an Analyst in our Response Lab. His reply was (and I’m paraphrasing here):

“Yes,  so that if anything happens, you’d know how the computer got infected, how to deal with the infection, and how to prevent it from spreading.”

Now, that’s the condensed version of a technical person’s answer. The real answer was actually a long, in-depth and detailed explanation covering how certain malware types had specific behaviors and particular vectors for distribution, as well as recommendations for dealing with particular types of infection.

And that there was the problem in a nutshell – it’s a lot of information to absorb. It was a thorough answer, but not an easy one to communicate to people with little interest in technicalities.  Some parts of the explanation also assumed more computer knowledge than most users would probably have or want.

Having said that, I thought the condensed version of our Analyst’s answer seemed like a helpful, ‘user-friendly’ answer. It summarizes all the main points effectively, puts it in a context most users would understand  and – this is important – it isn’t long-winded. I’ll come back to this again a little later.

Why A User Doesn’t Need To Know Malware Types

Trying to find a simple, all-encompassing answer to my friend’s question made me wonder if he really had a point and that users didn’t really need to know something as technical as malware types. So I decided to turn the question around and ask:

“Are there any cases in which ‘the average user’ doesn’t need to know the difference between malware types?”

The following four scenarios were the only ones I could think of where knowing malware types wouldn’t be helpful (if you can think of others, feel free to leave a comment). Of course,  I included some reasons why I think knowing malware types would be helpful even in these situations.

  1. I don’t do anything that might harm my computer.

    If you can honestly claim this, you’re probably what I’d call an Exemplary User: someone who diligently updates the operating system and programs, never installs programs or uses removable media without thoroughly vetting it first, doesn’t download from untrusted sources and basically, just does computer security right.

    An Exemplary User can laugh with scorn at looming malware outbreaks.  If this describes you, great! You can stop reading now. (Heck, you probably know the malware types already, anyway).

    Since the vast majority of users will never qualify for Exemplary Userhood however (myself included), the second best scenario is:

  2. MY computer can’t be infected.

    No, I’m not starting a PC versus Mac debate. What I mean is that even if malware does get onto your computer, it needs to find a suitable environment before it can have an effect. A Linux virus that somehow manages to get onto a Windows machine usually can’t do anything except blush sheepishly. Ditto for a backdoor that uses HTTP to connect to a remote site but ends up on a standalone computer without Internet acess.

    If your computer happens to be set up so that the majority of malware doesn’t target it or affect it (now you can start the PC/Mac debate), then our query becomes moot. Again, congratulations!

    Of course, most people have very little choice in the kind of operating system or programs they have on their computer, particularly business users. Even home users usually have to consider familiarity and affordability over specifically tailoring their computer to be malware resistant. To fix that, most users use antivirus protection. Which leads to reason 3:

  3. Why worry? My antivirus will remove it.

    Actually, since I work for a computer security company, I’d reeeaaally like it if more people could claim this. And hey – shameless plug – our Internet Security is doing pretty well in independent tests!

    Unfortunately, this solution isn’t 100% bulletproof, especially if you’re not an Exemplary User or are just plain unlucky.  Sometimes, the antivirus doesn’t catch the malware. Or it makes an error and the wrong file get fingered, causing all sorts of mayhem. Worse still, the antivirus turns out to be rogueware.

    In other words, the program you’re depending on to sort out all the problems….doesn’t. What then? Ah, then we move on to reason 4:

  4. Not my department. (IT/Tech Support/the computer guy) will just clean out any infection for me.

    OK, so the person fixing an infected computer should be the one with the technical knowledge, true. That person may not be the user, true. If you have someone dependable, willing and trustworthy, who can fix anything that goes wrong…can I have their number? Such a person is a godsend. Treasure him/her.

    Still, even if you’re that lucky, it’s often a great help to the actual technician if the user can pinpoint the probable cause. Knowing what type of dastardly program is screwing around with the computer gives the technician a good place to start investigating, and maybe also some idea of how to fix it.

    Or, to use an analogy, it’s the difference between driving to a workshop and telling the mechanic, “My car’s making a funny sound”, and saying, “The fan belt’s busted.”‘

And the Conclusion Is…

If you’re not in one of the 4 ‘Ideal Situations’ listed above, then it would probably be helpful for you to know the different kinds of malicious programs that can damage your computer, because…well, refer to condensed Analyst’s answer above.

Realistically though, learning about malware types, even superficially, requires investing time and energy that not every user can spare – which is why technical writers (ahem) have to find ways of communicating these concepts in ways that are interesting and easily accessible for everyone. Which brings us back to the condensed Analyst’s answer. It’s short, to the point and gives just enough information without being overwhelming. And if more information is asked for, well that’s the time to start going in-depth.

Personally, I like it – but since my part of my work deals with malware types anyway, I freely admit to being biased about this. So really, the best people to evaluate how useful that answer is – You, dear reader. So how about it? Do you think the condensed Analyst’s answer is a helpful, informative reply?


Oh and since we’re on the topic, here are the Types F-Secure uses to classify the samples – the good, the bad and the merely suspicious. You can also find plenty of other sites with excellent information on this topic – for example, has great articles explaining how trojans, viruses and worms work.

More posts from this topic

Mikko Hypponen

Mikko Hypponen’s Malware Hall of Fame

Mikko Hypponen is one of the world’s most prominent cyber security experts. Described as a “virus hunter” in a Vanity Fair profile called “The Code Warrior”, Hypponen has spent nearly 25 years with F-Secure protecting people from computer viruses, worms, trojans, and other types of malware. In 2011, Hypponen travelled to Pakistan to meet the men behind the first known PC virus – Brain.A. [youtube] The Brain virus was released in January of 1986, making January 2016 the 30th anniversary of this milestone in malware history. I thought it would be interesting to reach out to Mikko and ask him about other families of malware that standout as being noteworthy. So here’s Mikko’s list of some of the most infamous malware families (including viruses, worms, trojans, etc) that’ve pestered, frustrated, and even extorted computer users over the past few decades. 1990 Form – Form was a common computer virus identified in 1990, and for several years, was arguably the most prominent computer virus in the world. Spread through 3.5” floppy disks, it infected millions of computers throughout the world, and is possibly one of the most widespread viruses in history. 1992 Michelangelo – Michelangelo earns a place on the list for being the first truly global virus scare. It was named after the famous artist because the virus remained dormant until March 6 (the artist’s birthday), when it would awaken and overwrite sections of infected hard disks, thereby making the information inaccessible and the computer unusable. The virus was never particularly prominent compared to some of its contemporaries, but its destructive nature and subtlety helped spread Michelangelo Madness throughout the globe. 1995 Concept – Concept was the very first macro virus – a type of virus that infects applications such as Microsoft Word. It was a very prominent security concern in the mid-nineties, and even though it was successful in propagating itself organically during this time, it hasn’t been seen in over a decade. As the first macro virus, it was notable in that it spread by hiding itself as a Word doc and then infecting computers as those documents were shared. By using Word, it could use both Windows PCs and Macs to spread infections, as the software could run on both platforms. 1999 Melissa – Melissa, supposedly named after an exotic dancer, was a computer virus that sent infected Word documents to contacts in victims’ Outlook address book. While the virus was not designed to be particularly destructive, its rapid proliferation through the Internet wreaked considerable havoc on corporate servers and infrastructure. Some accounts claim that it infected twenty percent of computers globally, and the man eventually convicted of releasing the virus into the wild admitted to causing eighty million dollars in financial losses. 2000 Loveletter – Loveletter, also widely known as ILOVEYOU, was a prominent email worm that was able to spread itself throughout the globe in a matter of hours by promising victims a little bit of love. Disguising itself as a chain, love-themed email to recipients helped it quickly spread from its Filipino origin through Asia, Europe and North America. To this date, it is one of the largest malware outbreaks of all time, and responsible for an estimated 5.5 billion dollars of damage. 2001 Code Red – Code Red was the first fully-automated network worm for Windows. As in users would not have to interact with a machine in order to spread the infection. Code Red’s most infamous day was July 19th, 2001, when it successfully infected 300,000 servers. The worm was programmed to spread itself on certain days, and then execute distributed denial-of-service (DDoS) attacks on others, and was used against several different targets (including The White House). 2003 Slammer, Lovsan, and Sobig – Ok, so there’s three here and not just one. But they all occurred very close together, and unfortunately, all three were worms responsible for massive, global malware outbreaks. Slammer targeted servers so it’s presence wasn’t readily apparent to end users (save some lagging when they were attempting to access an infected server). Lovesan, however was able to infect end users running Windows ME or Windows XP, and use the infected machines in DDoS attacks. Sobig spread itself through email and network drives, and contained a trojan in order to cause more headaches for infected users. However, it appears that the trojan feature did not function as expected. These three worms infected millions of machines, and made headlines all over the world. 2004 Sasser – A computer worm that can be considered as the last large “hobbyist” outbreak. This is significant as it signaled the end of an era when most malware was written by people who were simply curious to see what the malware could do. Nowadays, malware has a more specific, insidious purpose, such as stealing information or making money. 2006 Warezov – A two-year email worm campaign perpetuated by professional criminals, Warezov gained notoriety for downloading new versions of itself from remote servers – sometimes as frequently as every 30 minutes, according to a 2006 interview with Mikko. 2007 Storm Worm (also called Small.dam) – Storm Worm was a trojan that was spread as an attachment to spam emails. But more importantly, it was a combination of complex and advanced virus techniques that criminals were able to use to make money by using infected machines as part of a botnet. 2013 Cryptolocker – A notorious ransomware family, Cryptolocker was spread through malicious email attachments, as well as the infamous Gameover Zeus botnet. Infected victims would find their hard drives suddenly encrypted, essentially locking them out of their devices and data until they paid a ransom to the perpetrators. While the FBI, in cooperation with other law enforcement agencies and security companies (including F-Secure), were able to disrupt the operation, the perpetrators were able to use Cryptolocker to extort about 3 million dollars from victims before being stopped. Other notable mentions include the 2005 Sony rootkit (for being distributed on Sony BMG CD-ROMs on their behalf), the still prominent Downadup worm from 2008 (for infecting millions, including armed forces of several countries and police departments), and the well-known Stuxnet virus from 2010 (for both its sophistication and its apparent state-sponsorship). If you want to know more about the history of computer viruses, you can check out Computer Invaders: The 25 Most Infamous PC Viruses of All Time!

January 29, 2016

Yes, it’s OK to play with scammers

This TED talk is so hilarious that I just have to share it with you. Watch it! British comedian James Veitch is engaging in the noble art of scam baiting, or scamming the scammers. The same as this site is dedicated to, or when I almost sold my boat to Mexico. I guess most or all of you already know how to spot an advance payment scam, aka. Nigerian scam. But James has some more to offer here. He’s making two important points, in addition to the excellent entertainment value. People often warns about engaging in any kind of conversation with these scammers. They are after all criminals and it’s safest to steer clear of them. I disagree, just like James. The people behind this kind of scams is not exactly the violent drug mafia. As a matter of fact, anyone who can use e-mail and Google Translate can set up a scam like this. And they are located in some poor remote country, typically in Africa. So it’s extremely unlikely that any of them would start hunting down people who play with them. That would disrupt their everyday business and cut profits, cost money and introduce the risk to get caught. But I do discourage people from engaging in scam baiting under their real identity. Set up a new mail account under a false name and never reveal any real contact info to them. You can reply from a different address than where you got the original spam. They are pumping out millions of spam messages and will not even notice the changed address. This adds an additional layer of security. And more important, it keeps your real inbox free of spam. Use their own tactic. Create a false identity with name, address, profession and country of residence. Stick to that story and make sure not a single bit of it is true. Read more about how to scam bait at The other point is that scam baiting is a good deed. It keeps the scammers busy and ties up their resources. Resources that otherwise would have been used to scam a real victim and cause real damage. A single scam baiter can’t of course save the world, but they would probably shut down if all of us spent an hour a week scam baiting. And it can be fun so why not? A good scam baiter can be a real pain in the a** for the scammers. Be prepared to get some threats and evil language when they realize what is going on. Consider that as a trophy, a proof that you did it right. Don’t feel bad for them. They did after all contact you with the sole purpose to scam you for money.   Safe scam baiting, Micke   Image: Screenshot from  

January 28, 2016