viruses worms Trojans and Bots are all part of a class of software called malware the overwhelming majority of malware is created to make money illegally Often by stealing sensitive and confidential information from victim's computers and mobile devices malware can also be used for cyber vandalism cyber Espionage activism cyber warfare and various other reasons malware can make entry onto your computer via questionable file downloads visiting infected websites or through email containing a seemingly benign link or attachment common types of malware viruses almost all viruses are attached to an executable file which means the virus may exist on a system but will not spread until a user opens the infected program viruses often originate on the internet and spread when downloading a file infected with a virus peer-to-peer file sharing or email attachment Trojan a Trojan is a harmful piece of software that looks legitimate users are typically tricked into leading and executing it on their systems Trojans can not only steal your sensitive data they can also give cyber Crooks access to your system Trojans are employed to gain access to your computer's financial and personal information ransomware ransomware holds your PC hostage and demand ands money it locks up your computer threatening to destroy data demanding Ransom or a payment for release of your data files or to regain the ability to use your computer again spyware spyware secretly gathers private information about the user activity such as internet usage and logs keystrokes via the process of key logging to steal passwords and other sensitive data worms worms can replicate themselves and infect multiple computers on a network causing major damage Network worms often use computer networks to spread slowing down traffic and relying on security failur such as outdated operating systems and no antivirus programs installed in contrast viruses require the spreading of an infected host file worms are a standalone software and do not require a host or human help to spread the best way to protect your system from malware is to keep your operating system system clean by downloading regular patches updates and making sure that your computer is protected by the latest antivirus software from a trusted vendor