Is malicious software designed to infiltrate or damage a computer system without the owners knowledge?

Malware is short for malicious software. It is any type of software designed to infiltrate or damage a computer system without the owner's informed consent. Trojans, viruses, worms, ransomware, and other threats fall into the category of malware. Good malware protection begins with effective antimalware software.

How to recognize and detect malware

Several symptoms are considered common signs of a malware infection, though many types of malware operate without alerting you to their presence. In fact, covert programs may be even more of a malware threat than overt ones, as they can lead to things like identity theft and credit card fraud. If you do notice something’s off, these signs may mean malware: 

• Performance problems- Computer running slowly or crashing frequently? Even small amounts of malware can slow or crash your computer by sapping hard drive resources while operating in the background.

• Unexplained PC behavior- If things are happening you didn’t initiate, you may be infected. Common changes in behavior include mysterious new toolbars, unexplained changes to homepage settings, and suspicious search results.

• Interruptions from pop-ups and spam- While many pop-ups and emails from reputable companies are safe, adware programs that generate malicious pop-ups are capable of installing spyware to hijack your browser and capture your personal information, even with reputable-looking ads.

How to remove malware from your computer

Prevention is the best strategy for keeping your personal computer free from malware. If your device does become infected though, it's not the end of the line. While manual malware removal is possible, it’s a complicated process even for savvy users. Still, there are ways to return your computer to a normal, functioning state. 

First, install a product with antimalware scan capabilities and run it on your system. This will help to determine your infection level and put your computer on the road to recovery.

Next, choose a more long-term malware protection solution. Look for these qualities when selecting an anti-malware software solution:

• It’s cloud-based for timely version and definition updates that combat up-to-the-minute threats

• It’s supported by a dedicated, round-the-clock research team devoted to keeping track of malware evolution

• It boasts an award-winning customer support team that resolves service tickets quickly

• It’s backed by an established company with a solid reputation

How anti-malware works and why you need it

To stand up to today's evolving threat landscape, effective antimalware solutions must offer multiple layers of protection. 

A good first layer is backed by a robust database of blacklisted URLs and IP addresses, updated in real-time, that should be blocked. Webroot's BrightCloud Threat Intelligence Services, for instance, classifies more than 27 billion URLs, more than any other service available, stopping threats based on knowledge previously gathered about their source. 

Next, a file without a known URL or IP is categorized as a known good or known bad file, or one requiring further inspection.
Then, heuristic or behavior-based layers decide whether to prevent a file from executing based on its intended action. If an action is unusual or harmful, this layer of malware protection will categorize a file as malicious.

Finally, a method known as sandboxing is often used to isolate a file when there is not enough information to make a ruling on a file’s category. Many antimalware solutions offer some type of sandboxing, but the speed and effectiveness with which this process is carried out vary greatly.

Only a small fraction of malware threats make it past the first layer of robust malware protection. But because of the sheer volume of threats facing the online users, a fraction still represents a serious threat. Just how pervasive is malware?

If you use a computer, you're susceptible to infection. In fact, nine out of 10 internet-connected PCs are infected with spyware that can:

• Expose you to identity theft

• Expose your personal information and private accounts

• Corrupt your hard drive

• Share your passwords and usernames

Read more about Malware Protection

Keep up with news on emerging malware and other online threats with the Webroot Threat Blog. 

If you’re interested in learning more about antimalware solutions from Webroot, let us help you choose the right product for you.
 

This page provides an overview of the most common malware applications. For specific steps you can take to protect against malware, see our Protect Against Viruses & Security Threats pages.

What is Malware?

Malware is a catch-all term for various malicious software, including viruses, adware, spyware, browser hijacking software, and fake security software.

Once installed on your computer, these programs can seriously affect your privacy and your computer's security. For example, malware is known for relaying personal information to advertisers and other third parties without user consent. Some programs are also known for containing worms and viruses that cause a great deal of computer damage.

Types of Malware

• Viruses which are the most commonly-known form of malware and potentially the most destructive. They can do anything from erasing the data on your computer to hijacking your computer to attack other systems, send spam, or host and share illegal content.
• Spyware collects your personal information and passes it on to interested third parties without your knowledge or consent. Spyware is also known for installing Trojan viruses.
• Adware displays pop-up advertisements when you are online.
• Fake security software poses as legitimate software to trick you into opening your system to further infection, providing personal information, or paying for unnecessary or even damaging "clean ups".
• Browser hijacking software changes your browser settings (such as your home page and toolbars), displays pop-up ads and creates new desktop shortcuts. It can also relay your personal preferences to interested third parties.

Facts about Malware

Malware is often bundled with other software and may be installed without your knowledge.
For instance, AOL Instant Messenger comes with WildTangent, a documented malware program. Some peer-to-peer (P2P) applications, such as KaZaA, Gnutella, and LimeWire also bundle spyware and adware. While End User License Agreements (EULA) usually include information about additional programs, some malware is automatically installed, without notification or user consent.

Malware is very difficult to remove.
Malware programs can seldom be uninstalled by conventional means. In addition, they ‘hide’ in unexpected places on your computer (e.g., hidden folders or system files), making their removal complicated and time-consuming. In some cases, you may have to reinstall your operating system to get rid of the infection completely.

Malware threatens your privacy.
Malware programs are known for gathering personal information and relaying it to advertisers and other third parties. The information most typically collected includes your browsing and shopping habits, your computer's IP address, or your identification information.

Malware threatens your computer’s security.
Some types of malware contain files commonly identified as Trojan viruses. Others leave your computer vulnerable to viruses. Regardless of type, malware is notorious for being at the root, whether directly or indirectly, of virus infection, causing conflicts with legitimate software and compromising the security of any operating system, Windows or Macintosh.

How do I know if I have Malware on my computer?

Common symptoms include:

Browser crashes & instabilities

• Browser closes unexpectedly or stops responding.
• The home page changes to a different website and cannot be reset.
• New toolbars are added to the browser.
• Clicking a link does not work or you are redirected to an unrelated website.

Poor system performance

• Internet connection stops unexpectedly.
• Computer stops responding or takes longer to start.
• Applications do not open or are blocked from downloading updates (especially security programs).
• New icons are added to desktop or suspicious programs are installed.
• Certain system settings or configuration options become unavailable.

Advertising

• Ads pop up even when the browser is not open.
• Browser opens automatically to display ads.
• New pages open in browser to display ads.
• Search results pages display only ads.