Showing posts with label Viruses. Show all posts
Showing posts with label Viruses. Show all posts

Saturday, September 22, 2012

The Most Notorious Computer Viruses

Thinking of throwing away your laptop because of a malfunction of some sort? Has a laptop part suddenly stopped functioning properly? Is a program which used to run great suddenly going haywire?

Before you chalk it up to hardware fault like damaged laptop components, you have to first make sure that it isn't just a virus attack of some sort. While just as harrowing as a laptop part malfunction, viruses can be easily taken care of with a competent antivirus program.

Of course, not all viruses are created equal; and while the viruses depicted below have long since had countermeasures developed for them, at the time of their infestations, they were notorious little buggers.

Here are the five worst of the lot.

1. Melissa

In 1999, a computer virus began spreading like wildfire via email messages. Called "Melissa," creator David L. Smith said he named it after a Florida exotic dancer. And in the same way that a dancer can allure you with a striptease, the Melissa virus tempted people to open these emails with the message "Here is that document that you asked for, don't show it to anybody else." Once opened, the virus then replicates itself by going after the top fifty people in the recipient's address book.

2. I Love You

A year later, another heavy-hitter emerged, this time from the Philippines. Among other things, it could copy itself several times and hide the replicants in various separate folders; add new files to registry keys; replace several important system files with copies of itself; and download a file called WIN-BUGSFIX.EXE (a password-stealing program) and run it.

3. Klez

In 2001, a year after I Love You hit, a far more sinister one came out of the woodwork. Klez, when activated, multiplied itself through a victim's email list much like Melissa, and rendered desktop and laptop parts themselves to be inoperable. Before it was totally eradicated, its creators even fine-tuned it so that it would be intelligent enough to copy the email address it was coming from.

4. Code Red and Code Red II

Also in the same year as Klez, the Code Red and Code Red II viruses appeared. These viruses exploited a weakness in the programming of the Windows 2000 and Windows NT operating systems. The weakness in question was the OSes' buffer overflow problem. This problem occurs when a computer receives more information than the system's buffers can process and starts to overwrite adjacent memory.

The first Code Red infamously attacked web servers at the White House by implementing a Distributed Denial of Service (DDoS) attack. This attack caused every infected computer to contact the White House's servers, thereby overloading them.

Meanwhile, Code Red II-infected computers were no longer operable by their owners because the virus created a backdoor program in their computers' systems, allowing a remote user to gain control of their machines.

5. Nimda

Still in 2001, a virus named Nimda (that's "admin" spelled backwards) spread throughout the internet. Nimda was notorious for being the fastest-spreading virus then, taking only 22 minutes to get from initial release to the top list of reported attacks.

Despite being able to infect home PCs just as well, its main target was internet servers, with the intention of slowing these down significantly. It travelled through the internet employing various methods, not the least of which was email propagation. This adeptness was what allowed it to multiply itself across thousands of servers in record time.

Abie Anarna is a blogger who specializes in writing about computers and various other electronic gadgets. Her educational background is in Information and Technology. She is very interested in all things tech-related; and has a particular inclination towards e-recycling, which is a prominent topic in her articles. She writes for LaptopAid, a company that also contributes to the e-recycling effort. In her spare time, she loves to read books and watch sappy rom-coms.



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Wednesday, September 12, 2012

Most Dangerous Computer Viruses on the Internet

Beast Trojan Horse - also known as remote administration tool (RAT)

Trojan horse is basically a standalone malevolent software program which cannot infect a computer automatically unless the virus is executed or the software program containing this virus. Once it gets executed, it will make numerous copies of itself and place them in multiple directories. In this way it can steal secret information from your computer by keystroke logging and damage the system completely. The beast Trojan horse has the capability to reverse connections which is also very harmful.

SQL Slammer - also known as Sapphire.

Its main feature is that it is a file-less worm. It spreads by taking benefit of vulnerabilities found mostly in SQL servers.

MyDoom - also known as Novarg

It is a mass mailer worm and holds the record of the fastest spreading worm. E-mail attachments are the prime areas which help to spread this worm. When an email attachment includes a subject line like "test", "error", "mail transaction failed", or "mail delivery system" in languages like English and French, then it means a virus. If this mail is executed then the worm is sent to the local files of the user's address book.

Black worm- also known as Mywife, Nyxem, etc.

This worm is spread through the emails that use External SMTP engine. The worm travels with different body texts, subjects, and the attachment names. Moreover, it creates multiple copies of itself and infects the hard drive with same name as in the windows file to remain hidden. The black-worm corrupts the data on every third day of the month. The worst part of this worm is that it can delete antivirus programs if both of them are placed in the same directory.

Bad Benjamin

This worm affects kazaa which is a common file sharing program. This worm is also found in movie and music files. This worm creates multiple copies of itself and anyone users who download movies or music files make their computers infected with this virus.

Numbing Nimda - also known as Concept virus

This worm has the capability to modify executable files and web documents. This virus creates multiple copies of it and spreads as embedded attachments in HTML mail messages. These corrupt e-mail messages when opened by the recipient allow the virus to reach the recipient's computer also. This dangerous virus can also move through server web traffic, a shared hard drive which are infected, downloads, and so on.

Expletive deleted explorer

This worm is so harmful that it can delete power point, excel, and word files along with other files. This virus travels via e-mails that come from a known recipient. The file containing this virus will show fake error message. It keeps a watch on the inbox of the infected system and then automatically sends replies to different senders.



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