This tip is intended to help you identify, classify malware and eliminate them from your computer. To make it more convenient I have divided the tip into two parts. This is the first part which discusses different types of malware, the next part will explain how to identify and eliminate malware.
The more we take to computers for day to day activities, the greater is the threat perception poised by malware. At this point in time the cyber threat we face has multiple forms like virus, worms,trojans, spyware etc. However, all malware do not affect equally, knowing the differences between them can help you avoid excess strain and tackle them more effectively. In this post, we will attempt to define, differentiate and eliminate these malware if possible through conventional means.
Virus – A computer virus is a self-replicating program that is intended to harm your computer through many ways. Depending on the type of the virus, damage done could vary from slight annoyance to a complete system disruption (I had a real bad experience with Chernobyl virus which corrupted BIOS ). Virus travel, mostly by attaching themselves to executable files, which are then sent to other computers by the unaware user. It propagates to other computers quickly but it cannot travel by itself and requires some user action.
Worms – A worm can be categorized as a sub-class of virus that can propagate itself without the user’s active participation or host file. Worms are especially dangerous in networked computers since it begins spread to other computers in the network and in the process congests network as well as consume all memory of the system. Lately worms are becoming a major threat because of their ability to take the network down.
Trojans – As the name implies Trojan Horse programs are programs that pretend to being utilities, games etc but when installed they compromise the security of the system. Trojans can neither replicate nor can they transfer, the only way to infect the system would be to actually run it on the target computer (or trick the victim into running it!). Popular Trojans when installed allow the remote attacker to take control of the victim’s computer completely. Some popular Trojans are also marketed as Remote Administration Kits, e.g. Netbus, Back Orifice etc.
Spyware– Applications that gather information about the user without her/his knowledge which is then transmitted to someone else for the purpose of targeting the user with customized advertisement. Apart from invading privacy these programs also consume the user’s system resources as well as bandwidth, adversely affecting performance which at times may be comparable to attack by computer virus.
Each of this program is difficult to detect or remove, which is why all of us depend on various anti-virus software and firewalls to protect us. While most of these anti-viruses are affective there are times when they become ineffective, especially when new malware arrive on the scene. Typically, anti-virus programs detect malware by matching the files with the signatures or definitions of known-viruses, present in their database. This is why it is important to update definitions from Web on a regular basis. Some anti-viruses also use heuristic methods, detecting suspicious activity and alerting the user but these alerts are more often raised for legitimate programs as opposed to malware.
The bottom line is that anti-virus applications do fail and fail pretty frequently too, depending upon the frequency of new virus strains being written and released. Being aware of the risk that malware pose can help you avoid getting your computer infected.