7 Malware

Malwares
Malware refers to malicious software designed to cause harm to users who are often unaware that they’re running it. This term covers various forms of malicious programs, such as viruses, worms, Trojans, ransomware, spyware, adware, and cryptocurrency miners.

Viruses
A computer virus is malware that replicates itself by inserting its code into host systems, such as data files or boot sectors of hard drives. Like biological viruses, computer viruses can spread quickly, but they need a host to do so. Some viruses cause noticeable damage to systems, while others may go undetected.
Although viruses continue to cause damage worldwide, worms and Trojans are more common today.


Worms
Worms are stand-alone malware that replicate and spread without needing a host. They usually propagate through networks by exploiting security vulnerabilities and can consume bandwidth, leading to slower connections even without altering data.

Trojans
Trojans are malicious programs disguised as legitimate software or hidden within non-malicious apps. They often spread through social engineering, tricking users into clicking links, installing software, or opening attachments. Unlike viruses and worms, Trojans rely on human error rather than technological self-propagation.

Ransomware
Ransomware is malware that demands a ransom to avoid harm, often by encrypting user files and threatening to delete the encryption key. Some forms of ransomware also steal data and threaten to publish it unless the ransom is paid. Ransomware can spread as a virus, Trojan, or even a worm.
Ransomware has become a major source of financial loss, with notable attacks like WannaCry causing billions in damages worldwide.

Scareware
Scareware tricks users into taking action by instilling fear. A common example is a message claiming the device is infected and offering fake security software for purchase to resolve the issue.

Spyware
Spyware is software that secretly collects information from devices, like keystrokes (keyloggers), video feeds, or screen captures. Spyware differs from invasive programs used by legitimate businesses, which may track online behavior but aren't classified as malware.

Cryptocurrency Miners
Cryptocurrency miners, or cryptominers, use infected devices’ processing power to generate cryptocurrency for criminals. These miners exploit the CPU of infected devices without the owner's consent. They have become widespread, especially during cryptocurrency booms.

Adware
Adware generates revenue by displaying ads on infected devices. It can be malware (installed without permission) or part of legitimate ad-supported software.

Blended Malware
Blended malware combines features of different types of malware (like worms, Trojans, and viruses) in one attack, making it more sophisticated and harder to combat.

Zero-Day Malware
Zero-day malware exploits unknown vulnerabilities, often making it highly dangerous. Creating zero-day malware requires significant resources and is commonly linked to nation-state attackers.

Fake Malware
Some criminals don’t bother infecting systems. Instead, they send fake warnings claiming the device is infected, demanding payment to fix non-existent issues. This tactic is common on both computers and mobile devices.