This is the second posting in a three-part series covering common threats a user may encounter.
This series serves as a rough and ready guide, highlighting key features and trends relevant to most users.
Viruses have always loomed large in users’ minds as the poster child of malicious programs – heck, we even call it the anti-virus industry. In the last 10 years or so however, the number of virus infections has nosedived; our Labs, which once dealt with viruses routinely, now sees a proper virus infection about once or twice a month. Today when people talk of ‘viruses’, more often than not what they’re describing is technically a trojan or a worm, and they’re using the term in a general, ‘any malware will do’ kind of way.
That’s not to say viruses are extinct; we still receive a small, if persistent, number of queries about viruses. This may be because many businesses, households and users (both in developed countries and in recently connected developing ones) still use old, out-dated, unpatched machines or programs, or haven’t yet developed a security-conscious habits.
Whatever the case, virus infections will probably still cling on to life for a weary day after, so let’s take a look at them.
The Merriam-Webster online dictionary’s bare-bones definition of a computer virus touches on important elements most users should know, so I’ll just elaborate a bit more on some key concepts:
Last week I compared a virus to a parasite, because not only does it ‘hide’ in another program, but also depends on its host to function. For the virus to run, the unsuspecting user must actively launch the infected program, which in turn launches the virus.
For this reason, virus writers usually create viruses that infect executable files (especially popular programs such as word processors or media files), which have a higher chance of being run; programs with files that get passed around a lot are extra attractive, since they can affect even more potential victims.
A good example is the Microsoft Office suite which, with their huge community of business and personal users, used to be a popular target for macro viruses. We still see queries related to this virus type, though thankfully far less than previously.
If you think of the common cold virus spreading from one person to another, you’ll have a pretty good idea of why this behavior can be so damaging. When a infected file is executed, it searches for and infects new files; if the newly infected files are launched, they find and infect new files in turn, like some evil Multi-Level Marketing operation. At worst, this pattern can lead to every targeted file on the system being infected.
The damage a virus can do by replicating and infecting new files is bad enough; its payload, a completely separate set of nasty actions, can be worse. The range of actions a virus can take is huge – connecting to a remote site, changing the desktop wallpaper, displaying silly notification messages, deleting data files…it really just depends on the virus author’s imagination and programming skills.
If you’re lucky, they’re not that good and you get failed viruses like Virus:W32/Stardust; if they’re good, then you get really nasty beasts like Virus:W32/Virut or Virus:W32/Sality.AA (one of the few viruses we still find regularly active).
With thousands of unique viruses out in the wild, antivirus companies find it necessary to divide them into sub-types. Unlike trojans though, viruses don’t fall into neat categories reflecting their actions; instead, they naturally fall into groupings based on technical differences in the way they infect a file – which is basically gobbledeegook to a user not interested in detailed analysis.
Gnerally, viruses can be divided into two groups – system infectors and file infectors. The majority of viruses are the latter and infect programs or data files. System infectors on the other hand write their malicious code to specific, critical sections of the hard disk containing the operating system, so that while the OS is running its normal routines, it’s also unintentionally executing the virus code.
Fortunately, for most users a virus’s classification is largely academic. For better or for worse, the sheer variety of possible effects each unique virus can have on a file or system makes it more practical to take each virus on a case by case basis.
So let’s go back to the original question that sparked off this series: do you really need to know if it’s a virus – as opposed to, say, a trojan or worm – infecting your computer?
Well, it helps to know because the two malware types tend affect your data and computer in different ways. As a (very) general rule, trojan infections is more about data theft and loss of control over the computer; virus infections tend to result in software disruptions or damage.
Trojans may copy and steal your data, but they don’t usually destroy the data file itself; they may stop programs from running but they don’t destroy the program. A virus on the other hand, insert its own code into a program or data file, and depending on how it does so, may either leave the host completely unharmed and functional, slightly disrupted, or completely non-functional.
Another difference between trojans and viruses that really affects the user involves disinfection. For one thing, a trojan is usually a single, discrete program – getting rid of it tends to be fairly simple, a matter of removing the malicious file and its residuals (registry keys, processes, icons, etc). Removing the trojan also generally doesn’t affect the integrity of other files on the computer.
Viruses are far more nebulous by design – they can be present in multiple files, in different locations. Identifying a virus-infected file may require scanning the entire computer to be sure every affected file is caught. Removing malicious code from an infected file or – if it can’t be saved, deleting the infected file entirely – can also be problematic if the damaged data is important or the program is a critical system component.
And this doesn’t even take into account the virus’s payload, which can produce a whole other set of worries.
Still, there is a ray of hope. If current malware trends persist, we may soon see adware or backdoors promoted to being the newest member of The Big Three, and viruses – as a distinct malware type – can finally be relegated to joining 3½” floppy disks in Computer Hell.
In the meantime, here’s some links to other, more in-depth resources on viruses:
Or partially available on Google Books:
Coming soon – Worms!
If you read our post about why you should travel with glitter nail polish, you know we love unconventional OPSEC advice that keep strangers out of your business. That's why this quote in a recent GQ profile of Kim Kardashian, which was first pointed out by LA Times editor Amy Fiscus, stood out: "She's frighteningly organized: She tells me that before bed she deletes every single text message and e-mail from her phone, unless it's something she still needs to respond to." Is this good OPSEC? We asked one of our resident experts Camillo Särs and he was intrigued. "Yes – the practice of deleting any unnecessary copies as soon as possible is definitely good OPSEC," he explained. "Clearly that is not the actual intent here, but effective, nevertheless!" So be like the woman who broke the internet, and consider getting rid of anything you don't need to keep as soon as possible. And if you're about to go on vacation, here's a quick OPSEC tip for your email out-of-office message, which could be helping criminals trying to phish you. Is there an OPSEC tip you picked up that you've picked up and feel like sharing? Let us know in the comments.
In Finland, there is this thing called juhannus. A few years ago, our former colleague Hetta described it like this: Well, Midsummer – or juhannus – as it is called in Finnish, is one of the most important public holidays in our calendar. It is celebrated, as you probably guessed, close to the dates of the Summer Solstice, when day is at its longest in the northern hemisphere. Finland being so far up north, the sun doesn’t set on juhannus at all. Considering that in the winter we get the never ending night, it’s no surprise we celebrate the sun not setting. So what do Finns do to celebrate juhannus? I already told you we flock to our summer cottages, but what then? We decorate the cottage with birch branches to celebrate the summer, we stock up on new potatoes which are just now in season and strawberries as well. We fire up the barbecue and eat grilled sausages to our hearts content. We burn bonfires that rival with the unsetting sun. And we get drunk. If that isn't vivid enough, this video may help: [protected-iframe id="f18649f0b62adf8eb1ec638fa5066050-10874323-9129869" info="https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Fsuomifinland100%2Fvideos%2F1278272918868972%2F&show_text=0&width=560" width="560" height="315" frameborder="0" style="border: none; overflow: hidden;" scrolling="no"] And because the celebration is just so... celebratory, it's easy to lose your phone. So here are a few ways to prepare yourself for a party that lasts all night. 1. Don't use 5683 as your passcode. That spells love and it's also one of the first passcodes anyone trying to crack into your phone will try. So use something much more creative -- and use a 6-digit code if you can on your iPhone. You can also encrypt your Android. 2. Write down your IMEI number. If you lose your phone, you're going to need this so make sure you have it written down somewhere safe. 3. Back your content up. This makes your life a lot easier if your party goes too well and it's pretty simple on any iOS device. Just make sure you're using a strong, unique password for your iCloud account. Unfortunately on an Android phone, you'll have to use a third-party app. 4. Maybe just leave it home. Enjoy being with your friends and assume that they'll get the pictures you need to refresh your memory. And while you're out you can give your phone a quick internal "clean" with our free Boost app. [Image by Janne Hellsten | Flickr]
Mikko Hyppönen -- our Chief Research Officer and probably the most famous code warrior ever to come out of Finland -- likes to point out that he was born the same year as the internet. Jani -- the ten-year-old from Helsinki who made international news by earning Instagram's top bug bounty prize for uncovering a security flaw in the photo-sharing site -- was born a couple a years after Facebook was invented in 2004 and just four years before Instagram went online in 2010. And he's already made some history. Jani discovered a flaw in the site that would have allowed him -- or anyone -- to delete content from any user from the site, even stars with tens of millions of followers including Taylor Swift, Selena Gomez and Beyonce. Like any good white-hat hacker he didn't take advantage of the vulnerability. Instead, he reported the bug to Facebook, which now owns the app, directly. His maturity paid off. Even though he is not technically old enough to use the site according Instagram's terms and conditions, he's become the youngest person ever to win a $10,000 bug bounty, which he's used to purchase a soccer ball, a bike and other essential gear for being ten. To celebrate his feat, F-Secure Labs invited Jani to visit our headquarters for a hamburger and a tour. The visit gave our experts a chance to share their stories about how they were drawn to cybersecurity. Mikko learned to love computers from his mother who was in the industry. Päivi was guided into the field by her father and discovered that she has a passion for rooting out spam. When Tomi was a kid striving to learn the rules of the coin games his friends played so he could hack them and win, he recognized that he didn't see the world like everyone else. Jani has already discovered the same thing. Though he finds plenty of time for school and playing with his friends, he spends 2-3 hours during his off days hunting for vulnerabilities and looking out for new bug bounty programs -- like our own -- that allow him to test his skills. How did he find the vulnerability in Instagram? First he created two accounts. He posted a comment using one account and then just using the publicly available content id number he was able to delete the comment using the other. Immediately he recognized the potential for such a flaw to be exploited. Mikko and Tomi were impressed by how Jani used Linux and Burp Suite -- a tool that pros like the analysts in our Labs use to analyze network traffic -- to help identify the bug. While he used to be interested in a career in video games, Jani says he's now thinking about becoming a cybersecurity specialist. Mikko and Tomi advised him to finish school and stay on the right side of the law. They also invited him to spend a week or two working at the Labs to see how he likes the job, when he's old enough. He's planning on taking them up on the offer, saying that F-Secure looks like a "fun and cool" place to work. Nice. We're always looking for new talent and even Mikko may retire one day.