10 Most Damaging Viruses And How To Handle Them
Viruses - what are the most harmful?
The history of viruses starts many years ago, practically, together with the history of the internet. They are developed for different purposes and sometimes are used, sometimes not. Some of them are very simple to remove and do not cause much damage, but there are those who created the virus history and are known as the most devastating viruses that have been ever developed.
Here, we will check what they are, when and why they were created and how to deal with them, if you suddenly notice such a visitor in your system.
Stuxnet - 2010
This was the first virus that was targeted not on the virtual world, but the real one. The aim of the developers was Iran uranium enrichment factory. The virus damaged the software that was controlling centrifuges, a significant number of which became uncontrollable and destroyed themselves. What is the most incredible about this virus, is that it was detected only one year after it was released. Of course, there are reasons why it happened like this. That was an unordinary virus, moreover, many believe that it has been developed by a Western intelligence agency. Then, in 2011 it got its continuation, in the form of a new virus, that was developed by using the code of Stuxnet – the Duqu virus. But this one was developed to steal information, not for causing damage to the industry. It uses the Windows vulnerability to get access to a computer, then installs there a rootkit to hide itself, but it not only ides itself, but also is able to hide injected code in a PLC.
Bitdefender – a proven solution even with the most devastating viruses
Nowadays, Bitdefender offers one of the most efficient tool for detecting and removal of Stuxnet. Other antivirus software that are able to detect and remove this virus efficiently, are DrWEB CureIt and Symantec.
Conficker Virus - 2009
This virus infects your system and allows to control your computer remotely. Just imagine which consequences it may have: theft of personal data, confidential information, financial information, access to your mail, profile in social networks. It is a very complex virus. It not only allows access to your data, but, if you want to remove it, it will block access to websites where you can download security products and disables Windows security services. Though, the strangest thing about it is, that it has never been used by its creators. It seemed that they developed it out of curiosity and forgot about it.
Most of antivirus software can handle it. Even though it infected millions of computers, it has never been used.
I LOVE YOU – 2003
This is the virus that has been the most damaging by now. Why? Many believe that it happened, because it is playing on the deepest feeling of the person – a need to be loved. The message comes in a mail with an attachment. Once a user opens the mail, its system is infected, and the virus send itself to ALL contacts in your address book. While another virus, Melissa, a similar one, was sending itself only to the first 50 contacts. Moreover, it is even not necessary to open this love letter mail, it is enough just to preview it to activate the virus. The, it overwrites some files in your computer, and the others are turned into relaunch points – in case if the system is cleaned from the virus. You remove the virus, but if some files stayed in the system, it will again relaunch itself from those files. The virus was coming through the mail, that is why, most users did not suspect, it was a virus. That is why it spread itself very quickly, it infected more than 10% computers in the whole world during ten days only. It cost more than 15 milliards of the US dollars to remove the virus, and the damage from it was more than 7 milliards US dollars. A good thing is that the developer was found, but the bad one is that it has been never charged for the damaged caused.
McAfee was the first antivirus that was able to cope with this “Love letter”. Then, other antivirus companies joined, too.
Agent.btz – 2008
This virus was created to steal data. It was so damaging, that Pentagon had to issue a blanket ban on the thumb drives, because the virus was spread with that means, and even a new military department was created, working in this field. The virus was overwriting files, creating copies of itself, created a backdoor that gave an opportunity to control a computer remotely, hence, providing access to all data stored in the infected computer, makes changes in the Registry, conflict with the security software, blocks your browser when you are trying to access a website where you can download a security software or its updates.
Most companies provide now a solution of how to handle this virus, though among the first and the best ones have been AVG and Symantec.
PoisonIvy – 2005
This virus gets into your computer through downloads from unverified sources, mail, USB devices and so on. It takes control over the system almost instantly after its download, it takes up the resources of your computer, slows down its work, causes crashes, it may slow down or stop your computer running some software. But the most dangerous thing about it is its backdoor, through which your computer continues being infected by malware of different kind, that enters the backdoor. This virus is very difficult to remove. Basically, after detecting it, which is not so difficult, you have to scan one by one all directories, and special attention shall be paid to the registry. The best solution though is to address to a professional.
Most software can deal with this virus nowadays, the most efficient though are Norton and F-Secure.
MyDoom – 2004
MyDoom was not only one of the most damaging, but also the fastest virus. It was arriving in a mail, sent from an infected computer. Then, after opening the mail, the virus was sending itself to all contacts in your address book. It allows remote access to the system and interferes with a security software installed in the infected computer.
F-Secure is able to remove most viruses
F-Secure and Kasperski antivirus solutions proved themselves as the most efficient ones in fighting with this virus.
Slammer – 2003
Slammer was dangerous and spread itself very quickly mostly because it was spreading via the internet. Once infected the computer starts sending in the net virus packets, hence, infecting other computers, that are connected to the net. The most danger of the virus was that it was damaging the servers that were responsible for the internet. The virus itself is not a file, it is a code. It doesn’t damage or rewrite anything, but it looks for vulnerable servers and performs their aggressive scanning. This, in turn, leads to their overload and the slow down of the internet, or even their disruptions. It doesn’t cause any damage to a computer itself, but services, that depend on the work of such servers, are damaged greatly. For example, this virus caused the Bank of America and some other services and enterprises stop their work, hence, causing a huge damage to the economy of the country.
For now, the most efficient antivirus products that remove the Slammer efficiently, are F-Secure, Symantec and Trend Micro.
CryptoLocker – 2013
This virus spreads itself through an infected mail, detachable device, with downloads containing the virus. Once it gets to the system, it blocks all data and encrypts itself. For unblocking of data, it demands money, in this case it is 400 USD. Of course, you can remove CryptoLocker with an antivirus software, but as we mentioned, the virus encrypts itself. The most unpleasant thing was, that the virus used very long keys, hence, unblocking the blocked files other than paying for the key, was impossible. The only way to restore the blocked information without paying was to have its backup copy, but very few users had it. Hence, more than half of million of computers were infected, and users paid about 30 millions of dollars.
While it can be removed by Kasperski, McAfee, but the only way to get your data back is either to pay or to use a backup copy.
Flashback – 2011
A short background story comes first, to explain, why we included this virus in the list, even though it hasn’t caused so much damage as the others, that are included here. You may already know, that Apple produces both hardware and software for its devices. That is why they are extremely safe, they are fitted perfectly to each other and practically do not have vulnerabilities, which can be exploited by malware. Well, Flashback showed, that MAC is vulnerable, too. This was the first virus, that infected the MAC! That is why even though it is not the most devastating, but deserves being mentioned. It can infect those MACs where Java is installed, as it exploits Java vulnerabilities. The good news that it infects one user account only and one can get it only when one downloads it. The bad thing is that it is difficult to remove, and it was so unexpected, that still, many MACs were infected.
It can be removed with DrWeb and Kasperski. Also, Apple released the vulnerability fix, which allows avoid infecting with this virus.
Zeus – 2007
This Trojan virus infected computers either through infected downloads or through phishing scam. Its main target was stealing of information – personal, financial – all kind of information, stealing of passwords to all kinds of sources, such as social networks, private networks and business networks, public as well as private. This virus affected the work of many financial and trading institutions, such as banks, online stores etc. the virus collects all kind of information in different ways, for example, adds a new field in the login page, say, of an online banking website. Moreover, it allows remote control of your computer. The hacker that targeted your computer can remove or change files, spoil software, hence, causing disruptions and crashes of your system, which will lead to the reinstalling of the whole OS.
Symantec and Kasperski have proven themselves as the most efficient tools in removing Zeus and eliminating its damaging effects. But to remove it is not enough to have your system back safe and sound. After removal the virus, you have to run a special application, that stops the malicious processes, initiated by Zeus, only after that you may feel yourself in safety.