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Digital threats

Biswajit.HD

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In recent years, consumers have become more tech savvy and have a better understanding of the mysticism of the Internet. From banking and shopping online, keying in our user IDs and passwords and confidently sharing our personal information at secure sites, these are everyday occurances. Although it makes our life easier, our increasing online usage also makes us vulnerable to digital threats. When we enjoy the convenience of online banking, we invariably expose ourselves to phishing attacks. We download applications from the Internet and invite malware to take control of our computers. Email attachments may unknowingly bring in Trojans that might play havoc with our computers. However, if we exercised a little more caution, we could prevent the threat of malware from capturing our online identity. To do that we need to be aware of the different types of risks that exist, how they work and what can be done to safeguard our data against them.

Danger defined :

By and large, we tend to categorize all online threats as viruses. But what really is a virus? Historically speaking, a virus is a type of a computer program that not only infects your computer, but makes multiple copies of itself and proliferates within documents or applications on your computer. It also has malicious reprecussions like corrupting file content, denying access to databases, stealing personal information and the like. Back in the days of the floppy disk, an infected disk could infect a host computer if the user executed or copied files from it. This digital plague could further infect other floppy disks or other media if inserted into the host computer, thus replicating them. To prevent these viruses from spreading and damaging files, computer security firms developed applications that could detect and even remove viruses within files. In cases where this disinfection was not possible, the program would delete the file from the computer or move it to a secure location (much like a quarantine). However, today’s virus engineers are smarter. Drawing on the power of the Internet, there are very few viruses out there that still spread by physical media—most viruses proliferate through the Internet across various programs. This has given rise to worms that travel through local and web networks, Trojans that are capable of camoufl aging their presence and spyware that can steal your data without your knowledge. Welcome to the new world of malware.

Computer worm:

In computer terminology, a Worm is a self-replicating threat that travels through a network and settles in a computer via a variety of online applications like e-mails, chat clients, P2P clients, etc. A worm does not attach itself to any program that explicitly needs to be executed for its spread. Instead, it travels through networked applications and primarily replicates itself up to a point where the network is clogged with its clones, preventing it from being used by legitimate applications. The different types of worms you could encounter are:

E-mail worm:

This type of worm uses e-mail as its vehicle. When an infected e-mail reaches your inbox, it does nothing unless the e-mail is opened to be read. When you open the mail, you may see an attachment or a link to a real or fictitious web site. The moment you click on the link and visit the web site, the worm gets triggered. Once activated, it starts searching your address book and sends e-mails to your contacts. It can even fake the sender’s address, so that the recipient assumes that the mail is not from someone he knows. Clearly, across an office network consisting of tens or hundreds of users, the numbers of ficticious e-mails traversing the mail servers grow exponentially over a short time. E-mail worms often bring down mail servers and clog their functioning.

File sharing network worm:

This worm generally proliferates through a shared folder of a machine. It creates a copy of itself and masks its intent by using a seemlingly harmless and unassuming name. The moment you connect to a networking site like ‘kazaa.com’ and your sharing folder gets accessed, the copy of the worm moves from your computer to other computers in the file sharing network. With millions of computers actively being used to access files from peer-to-peer networks, these worms can proliferate very quickly. Another popular type of worm is the instant messaging worm (similar to the email worm, but uses an instant messenger service as its vehicle).

Trojan:

Trojans are malicious programs that pose as legitimate applications. When users execute such programs, blissfully unaware of their real intent, the host computer gets infected. Once on your computer, it may strike in a variety of ways, ranging from capturing what you see on your screen to logging what you type. The captured information is then sent to the author of that malware through the Internet. You could therefore stand to lose precious data, bank passwords and the like. The different types of Trojans include remote access Trojans, where others can gain access to and even take over your machine, data sending Trojans that scan your computer and send data to the author, and destructive Trojans that simply delete files on the host computer. Trojans can also infect your computer and you may face denial of service (unavailability of data). Trojans even have the potential to counter anti-virus software by changing their coding DNA (a process known as polymorphism), making it harder to detect. Some Trojans are developed such that they will only be activated on particular dates, or when certain pre-defined conditions are met by the computer. These Trojans are known as ‘Time bombs’ and ‘Logic bombs’ respectively. Spyware Like Trojans, Spyware is also a type of computer application, developed with the intention of stealing information from your computer. These applications can steal data including the history of web sites you have visited, passwords that you have used to access online secure services, etc . However, unlike Trojans and worms, spyware cannot replicate but it does exploit the host computer for commercial gain. These include everything from throwing unsolicited pop-up advertisements, capturing your web browser’s home page and directing it elsewhere. This type of application cannot spread by itself, therefore its efficacy depends solely on whether you choose to install the software. Since users wouldn’t intentionally install applications that are detrimental to their interest, spyware represents itself as a utility application, for example, a web accelerator, a free image utility, etc. Spyware often piggy-backs on to shareware applications found on download web sites or application CDs.

Adware:

Adware is more of an annoyance than a threat. Typically found in applications downloaded from questionable web sites, it infects the host computer by downloading and installing other advertising material and displaying it on your computer via annoying popups that appear while you use Internet applications. This is where adware generally gets confused with advertising-supported software. The latter is not malicious and only displays an advertisement within the window of the application program (such as trial or shareware versions of software). Adware, on the other hand, displays advertisements randomly, often when you least expect it.

The last call:

This new breed of Internet threats may or may not be harmful to users, but they do hamper the performance of computers. To protect computers from today’s digital threats, an anti-virus program is a good place to start. Look for application suites that specifically offer protection against all of these threats and not just ones that offer plain vanilla virus protection. In today’s world, data security requires blanket protection systems that do it all. You can also install anti-spyware and adware application like NoAdware, ErrorDoctor, Spynukke, AdAware, etc. Secondly, it is important to exercise caution on what applications and fi les are downloaded. This includes your mail attachments. Chain mails with attachments (such as .exe, .com, .scr, .bat, or .pif), download sites that contain links of questionable web sites, applications that aren’t from trusted sources should all raise a user’s alarm bells. Most of the time, the battle against malware can be won before it even begins—all it takes is a bit of vigilance.

Source : Chip magazine.
 
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