Top 10 Most Dangerous Computer Viruses of the Decade Updated 2012

Computer was invented and hence the computer virus was, Computer helps us but viruses makes a lot of problem to almost every computer user and has been considered as the biggest problem in Computer & Tech world till date.

Basically a computer virus is a software program created with wrong intentions such as to hack a computer, get confidential data and many other like these and that is why it is very important for every computer to know at least about Top 10 Most Dangerous Computer Viruses of 10 years that is 2002 to 2012.

So I worked very hard to find out the list of these Top Ten Most Dangerous Computer Viruses, so thought to tell everyone via this post.

1. Beast Trojan Horse (2002)

Also Known As: Remote Administration Tool or RAT (Now This is a Type)

First understand what is a Trojan Horse is ? and what it can do ? Trojan Horse is a standalone malicious software program that does not infects computer completely automatically, until  you execute the virus or infected software program it does nothing but once executed it can make copy of itself in multiple directories and hence makes difficult to be removed, it can steal your secret information by many ways such as keystroke logging or can damage your computer system completely.

And Beast is one of the first Trojan Horse program that has capability of reverse connection, this program was written in Delphi programming language by Tataye in 2002. It was using the injection method to inject viruses into specific process, commonly “explorer.exe” (Windows Explorer), “iexplore.exe” (Internet Explorer), or “msnmsgr.exe” (MSN Messenger) to steal information and give control to its author of your computer.

Once it connects to its author, they can do the following on your PC:

  • Access to File Manager – along with browsing victim’s directories it could upload, download, delete, or execute any file, hence becomes more dangerous.
  • Remote Registry Editor
  • Get Screenshot of your computer Screen and your Webcam
  • Passwords tool capable of recovering any stored passwords in the victim’s computer
  • Access over Power Options (e.g. shutdown, reboot, logoff, crash, etc.)
  • Also included a Chat client for providing communication between the attacker and the victim
  • Other tools such as a Remote IP scanner, live keylogger, offline logs downloader, etc.

2. SQL Slammer (2003)

Also Known As: Sapphire, Worm.SQL.Helkern, SQLSlammer

Appeared at the starting of the year on 27th January 2003 and very quickly it got the highest rank in the list of most dangerous worms of that year because it was the first fileless worm. SQL Slammer was able to spread by taking advantage of the vulnerability found in the SQL Servers.

According to statistics: SQL Slammer spread to over 90 percent of all vulnerable hosts in 10 minutes and infected around 359,000 Hosts total and according to London-based market intelligence the worm caused between $950 million and $1.2 billion in lost productivity in its first five days worldwide.


Year 2003 has been one of the Most Destructive year in tech world as it got more than one more dangerous Virus, at the end of the year on 12 August call Blaster, According to Estimate it caused Damaged worth 10 billion dollars and on August 19 worm name Sobig worm has been detected which caused damage of 7 billion dollars and infected over 1 million PCs.

3. MyDoom (2004)

Also Known As: W32.MyDoom@mm, Novarg, Mimail.R and Shimgapi

First seen on 26th January 2004 and it caused Damage of $38 Billions. MyDoom is still the current record holder for the fastest-spreading mass mailer worm.

Mydoom is primarily spread via e-mail attachments, it comes in email with subject lines including “Error”, “Mail Delivery System”, “Test” or “Mail Transaction Failed” in different languages, including English and French. The mail contains an attachment that, if executed, resends the worm to e-mail addresses found in local files such as a user’s address book.

Next day on 27th January SCO Group offers a US $250,000 reward for information leading to the arrest of the worm’s creator.

4. Bandook Rat (2005)

Also Known As:, Troj/Bandok-J, Backdoor.Bandook, BDS/Bandok.R.2

A very similar virus as Beast Trojan Horse (2002) but with improved functionality detected first in middle of 2005. Bandook Rat abbreviation for “Bandook Remote Administration Tool” is a backdoor trojan horse that infects Windows NT, 2000, XP, 2003, Vista, Windows 7 Also, Yes that means new variants of this virus is still being released by different authors and hence making it the most destructive virus till date.

5. Blackworm (2006)

Also Known As: Mywife, Hunchi, I-Worm.Nyxem, Blackmal, Nyxem, Blueworm

Blackworm worm was first virus of 3 found on 20 January, 2006. The worm spreads in e-mails using an external SMTP engine. It sends itself with different subjects, body text and attachment names. The worm also copies itself multiple times to an infected hard drive with similar name as windows files in order to be hidden. Blackworm is designed to corrupt data on infected computers on every 3rd day of each month, in respect to The Day the Music Died. After corrupting the data of the computer it visits a webpage with tracking code, so it can be counted how many Systems has been infected, and over 300,000 unique IPs visited that site.

The most scary thing in this worm is, It can deletes your antivirus programs if they are installed in the same directories as the ones specified in the worm’s code. It can also delete the entries in the Windows Registry belonging to these antivirus programs, so antivirus applications will not be run automatically the next time Windows is started.

The worm also contains one GIF file which is used to make a recipient of infected e-mails think that the message was scanned by Norton Anti-Virus and no infection was found.

But its havoc ended soon and it gone off the records after October 26.

Did you Know: By the time you will finished reading this article 95,000+ new computers has been affected by viruses ! This article is half because -
More long article = More time required to read = More computers are affected.
Filed in: Technology News Tags: computer, software, technology