Malware is short for “malicious software” meaning software that can be used to compromise computer, steal sensitive data, cause harm to the computer or bypass access controls. Obviously, this is a variety of malicious program that define the most common types of malware; adware, bot, bug, ransomware and rootkit. 1. Adware Adware is a type of malware that downloads or display advertisements to the user. It forces users to see advertisement rather that they would rather not have on their computer. As a common example, adware includes pop-up ads on websites and software and it is displayed by software. Usually, software offers free version with adware that serves as a revenue generating tool. The adware generates browser pop-ups that cannot be closed and users unknowingly infect with adware that is installed by default when users download or install other application. 2. Bot Bot is software programs created to automatically perform specific operations. Some bots are not harmful and created for harmless purpose, but these days they are used maliciously. Bot can be used in botnets for DDoS attack, as spambots and web spiders. 3. Bug Bug is a flaw in a piece of code. These flaws usually come out due to the human error and exist in the source code or compilers of a program. Bug represents serious security vulnerability and it can allow attackers to bypass user authentication, override access privileges or steal sensitive data. 4. Ransomware Recently, ransomware has quickly become one of the most prevalent types of malware. It essentially holds a computer system captive while demanding a ransom. The most common malware restricts user access to the computer either by encrypting files or locking down the system. Attacker forces users to pay to remove the restriction and regain access to their computer. 5. Rootkit Rootkit is a malware designed to remotely access or control a computer without being detected by users or security program. Once attacker has root access to computer system, he/she can do anything that they want on computer system including recording activities, changing system setting and accessing data. As rootkit continually hides its presence, it is hard to prevent, detect and remove it. Here is the simple way to detect malware that is installed in your computer system unknowingly. WMD is web security service which provides malware detection and checks whether to be malware's origin / spreading point or not by early action. WMD inspects website intensely by visiting URLs and analyzing multi-level and detects malware through static and dynamic analysis engine (Cloud Artificial Intelligence platform, AICC). WMD enables you to take early action to protect your website.