What is a Malware (Malicious Software) ?
Malware or malicious code (malcode) is short for malicious software. It is a code or a software that is specifically designed or created to damage, disrupt, steal, or in general inflict some other “bad” or illegitimate action on data, hosts, or networks.
Malware cannot damage the physical hardware of systems and network equipment, but it can damage the data and software residing on the equipment.
Examples of Malware:
- back doors
- bots etc
The Difference between Malware & Defective Softwares ?
Malware should also not be confused with defective software, which is intended for legitimate purposes but has errors or bugs.
Malware designed or created intentionally for illegitimate purposes to damage date or softwares of host computer.
Defective softwares is created for legitimate purposes but due to the mistakes or holes or bugs or error unintentionally done by programmers it becomes defective.
What is the Difference Between Virus & Worms ?
Two of the most common types of malware are viruses and worms. These types of programs are able to self-replicate and can spread copies of themselves, which might even be modified copies. To be classified as a virus or worm, malware must have the ability to propagate.
The difference is that a worm operates more or less independently of other files, whereas a virus depends on a host program to spread itself. These classes of malicious software are described below.
What are Viruses?
A computer virus is a type of malware that propagates by inserting a copy of itself into and becoming part of another program. It spreads from one computer to another, leaving infections as it travels. Viruses can range in severity from causing mildly annoying effects to damaging data or software and causing denial-of-service (DoS) conditions. Almost all viruses are attached to an executable file, which means the virus may exist on a system but will not be active or able to spread until a user runs or opens the malicious host file or program. When the host code is executed, the viral code is executed as well. Normally, the host program keeps functioning after it is infected by the virus. However, some viruses overwrite other programs with copies of themselves, which destroys the host program altogether. Viruses spread when the software or document they are attached to is transferred from one computer to another using the network, a disk, file sharing, or infected e-mail attachments.
What are Worms ?
Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage. In contrast to viruses, which require the spreading of an infected host file, worms are standalone software and do not require a host program or human help to propagate. To spread, worms either exploit a vulnerability on the target system or use some kind of social engineering to trick users into executing them. A worm enters a computer through a vulnerability in the system and takes advantage of file-transport or information-transport features on the system, allowing it to travel unaided.