Malware, short for malicious software, is any software intentionally designed to cause damage to a computer, server, client, or computer network. Unlike software that causes unintentional harm due to some deficiency, malware is developed with the explicit intent to inflict harm or exploit devices for the gain of others. The term encompasses a variety of forms of hostile, intrusive, or annoying software or program code.
Malware includes a wide range of malicious software types, such as:
- Viruses: These are malicious programs that, when executed, replicate themselves by modifying other computer programs and inserting their own code. Infected systems might experience degraded performance, data loss, or unauthorized access to personal information.
- Worms: Similar to viruses, worms can replicate themselves across a network without the need for a host program. They typically exploit vulnerabilities in operating systems or other software to spread without user intervention.
- Trojan Horses: These are malicious programs that mislead users of their true intent. Unlike viruses and worms, Trojans do not replicate themselves but they can be just as destructive. They often pose as legitimate software or are hidden within legitimate software that has been tampered with.
- Spyware: This type of malware covertly collects information about a person or organization without their knowledge, often leading to privacy violations and significant security risks.
- Ransomware: This malicious software denies access to a system or personal files and demands ransom payment in order to regain access. It has become a significant threat to businesses and individuals alike.
- Adware: Although sometimes legally used software, adware can be considered malware when it’s deployed without the user’s consent and redirects the user to unwanted advertising material, or when it tracks user activity without permission.
- Rootkits: These are designed to enable continued privileged access to a computer while actively hiding their presence from administrators and other system protection mechanisms.
The methods of distribution and infection can vary significantly, from email attachments and malicious websites to exploiting vulnerabilities in network services and software. The intent behind malware can range from vandalism and theft of sensitive information to espionage and financial gain. Combatting malware involves a combination of cybersecurity measures, including antimalware and antivirus software, firewalls, careful practice of digital hygiene by users, and regular software updates to patch vulnerabilities.