<human>:  What are the different types of computer viruses and their effects?
<bot>: Trojan horses – These viruses are designed to look like harmless files, but they can cause major damage when executed. Common effects include allowing remote access to the infected computer, allowing your personal information to be stolen, and deleting important files.2Worms – This type of virus spreads itself throughout a computer system on its own, often over a network. It can consume system resources, spread to other computers, and even cause denial-of-service attacks.3Adware – Adware is a type of virus that displays unwanted advertisements on the computer. It can also slow down system performance, generate intrusive pop-up ads, and reroute web searches to unwanted locations.4Spyware – Spyware is a type of virus that plots secretly to steal sensitive user data, such as passwords and credit-card numbers. It can be used to hijack accounts and e-mail addresses as well.5Ransomware – Ransomware is a type of virus that locks your computer system until you pay a fee to receive a key for unlocking it. It can encrypt files, modify system settings and even erase data.