You know that viruses are bad for your system, but they are just one type of malicious software. Broadly speaking, malware is any software developed to disrupt your computer or device's normal functioning. Malware is often used to steal, to spy, or to destroy. It can target your personal information, corrupt your files, spam your contacts, use your computer for nefarious purposes, or even render it useless.
There are currently over 375 million malicious programs out there, with another 390,000 recorded each day, according to AV-Test. In recent months, the number of total malware threats has increased by 13 percent, and mobile malware is growing even faster, with the number of new incidences skyrocketing by 49 percent, according to McAfee (PDF link to report). Don't ignore the onslaught -- get to know your coded enemies and learn how to defeat them.
Types of malware
- Adware: Displays unwanted pop-up ads.
- Backdoor: Installed by Trojans or worms in order to enable continued access to your computer without your knowledge.
- Browser hijacker: Changes your homepage settings or adds a toolbar to gain personal info to sell to third parties.
- Rogue security software (aka rogue AV): Fools you into paying for a "clean-up" that is actually further infection.
- Keylogger: Surveillance software that records your every keystroke. Combined with spyware, keyloggers can send all your keystrokes -- including passwords and personal info -- to third parties without your knowledge.
- Ransomware: Criminals encrypt your hard drive data and demand payment to unlock the files.
- Rootkit: Stealthy software that modifies your system so that you can't detect interference from malicious processes or programs, thus guaranteeing continued access to your system.
- Spam: Unsolicited mass-mailed ads that come via email, SMS, instant messenger, or Internet phone software.
- Spyware: Logs and stores your Internet activity and may also install Trojans.
- Trojan: Malware that tricks you into installing it so it can steal your data or damage your system.
- Virus: Infectious malware that installs itself in your other software, files, or hard drive and propagates itself.
- Worm: Infectious software that spreads most often via computer networks.
How to avoid malware infection
Sometimes malware enters your system uninvited, but other times you're welcoming it in. To avoid invasion:
- Download software from reliable sources only. A lot of mobile malware, for example, comes from outside Apple's App Store and Google Play.
- Read an app's End User License Agreement (EULA) before you download or update software, to make sure that no extra software is bundled with the app you want.
- Don't click links, attachments, or offers from untrusted sources. Some hackers are clever about spoofing email, phone, or social media accounts, so before you click, ask yourself whether your contact would send you that file or link.
- Keep your system and software up-to-date to get the benefit of recent fixes and patches for known vulnerabilities.
How to remove malware
Once malware is in your system, it is often hard to detect and remove. You may notice certain symptoms: slow performance, changes to your browser behaviors, browser instability, added toolbars, loss of application functionality, an increase in ads.
If you suspect that you're a victim of malware, you have several options for removing it. Let's start with the built-in tools. Rudimentary software such as Microsoft Windows Defender and Mac's XProtect are available, but they're not terribly helpful -- they only warn you against running the most common, blacklisted malware but don't actually remove any of it. OS X users have Gatekeeper, which will permit apps to launch only if they are (a) downloaded from the official Mac App Store, (b) created by trustworthy developers, or (c) signed by the developer.
Your best bet is a good third-party antimalware program. For Windows and Android users, Malwarebytes (Windows, Android) is a consistent favorite, or check out our list of nine apps for rescuing your PC from malware. For Mac users, Avast Free Mac Security 2015 is an excellent choice. iOS users should check out Trend Micro Mobile Security.