It seems that nowadays cybercriminals prefer cash to fun. That is why malicious programs of various kinds (viruses, worms, Trojan horses, etc.) are very often aimed at stealing valuable -- in a direct sense of this word -- private and financial information. When written, these programs are spread all over the Web.
What do means of their distribution have in common? Thinking a bit about it will help us ordinary Web users realize how to behave online and what to avoid.
Let's use logic and good old common sense. What do you think are the most suitable (for a criminal)means to spread malicious code? The answer is almost obvious. It is something which, first,ensures his anonymity and, second, offers victims (i.e. us) very little or no protection against malware. Last, but not least -- this means should be very cheap or, even better, free.
(I'll confine myself to mentioning only those means which endanger EVERY Internet user. Not everyone exchanges files or downloads music and freeware. But is there anybody who doesn't send and receive email or visit websites?)
Well, if you were a cybercriminal who wanted to spread a malicious program quickly and as widely as possible, how would you distribute it?
What first comes to mind? First, sending contaminated emails through spam. It is possible (and not too difficult for, say, a programmer) to enclose virtually anything into the attachment. With more effort, a programmer can create a message without any attachments that will infect a PC anyway.
Though many email service providers offer basic anti-virus protection, they aren't obliged to do it. How effective this protection is -- that's another question.
Besides, spam is very cheap to distribute. Of course, spammers of all stripes don't use their own machines. Why should they? They prefer PCs which became remotely controlled after being infected with a special program. Cybercriminals build huge networks of such machines and hire them out to spammers. Using "bots" (they are also called "zombies" or "slave computers") gives a spammer so valued anonymity -- spam messages come to frustrated PC users from IP addresses registered somewhere on the other side of the globe.
What about other possibilities? Websites. Malicious websites are very dangerous.Cybercriminals create them exclusively to execute malicious code on the visitors' computers. Sometimes hackers infect legitimate sites with malicious code.
When unsuspecting users visit malicious sites, various nasty applications are downloaded and executed on their computers. Unfortunately, more and more often these applications contain
keyloggers--software programs for stealing information.
Keyloggers, as it is clear from the name of the program, log keystrokes --but that's not all. They capture everything the user is doing -- keystrokes, mouse clicks, files opened and closed, sites visited. A little more sophisticated programs of this kind also capture text from windows and make screenshots (record everything displayed on the screen) -- so the information is captured even if the user doesn't type anything, just opens the views the file.
Blogs can be contaminated with malware, too. In April experts from Websense Security Labs warned users that they discovered hundreds of these "toxic" (contaminated with malcode) blogs set by hackers. Blogs are suitable for them: there are large amounts of free storage space, no identity authentication is required to post, and there is no scan of posted files for viruses, worms, or spyware in most blog hosting services.
Three months passed, and here is the quote from a new Websense report released this Monday, July, 25th : "hackers are using free personal Web hosting sites provided by nationally- and internationally-known ISPs to store their malicious code..." This July Websense detected that these sites are used for this purpose much more often. The company's senior director of security and technology research said that "in the first two weeks alone we found more instances than in May and June combined." By all means it's a tendency, and a very disturbing one.
Such sites are free and easy-to-create. With the average lifespan of between two and four days, they are difficult to trace. Free hosting services rarely offer even basic security tools. Short-lived websites,no files scanning for viruses, nothing prevents "authors" form uploading executable files - isn't such a site an ideal tool for distributing malicious code?
Anonymity of the creator -- no end user protection -- no cost. What else can a cybercriminal wish? That is why there was the outbreak of "toxic blogs" in April - and that's why infested free websites are multiplying so quickly now.
But how to contaminate as many computers as possible? It is the aim of cybercriminals, isn't it? The more traffic, the more programs lands on end users' computers. Hackers attract traffic to malicious websites by sending a link through spam or spim (the analog of spam for instant messaging (IM).
They are ingenious in finding new ways to make people open an attachment or click on a link to visit a certain website, though people are constantly told not to follow links in spam.
Just some of their dodges -- disguising infected spam emails as CNN news alerts, subject lines with "breaking news" like "Legit hackers for hire bin Laden caught", "Michael Jackson tried to commit suicide". How about celebrities in the nude? Just click! And, one of the latest, an "amateur video" that ostensibly shows London bombing sights.
These (and similar) tricks are usually called social engineering. Online criminals have become good psychologists -- the big bucks which crimes like online bank fraud can bring turned them into earnest students.
However, there is one thing that spoils the mood of those who spread malicious programs.
To hackers' deep regret, people become more aware of the risks they face in the Internet. A study by Pew Internet and American Life Project released on July 6th shows that:
91% (!) of respondents (adult Internet users from the U.S.) changed their behavior online one or way another.
81 % have become more cautious about e-mail attachments
48 % have stopped visiting certain websites which are said to be harboring malicious programs People stop using file-sharing software (25%) and even start using Mozilla, Firefox or other browser instead of Internet Explorer (18%)