Malware is any software that infiltrates devices without the owner’s knowledge to cause disruption or theft of information. Examples include viruses, worms, spyware, adware, botnets, and rootkits.
Some telltale signs of malware infection are frequent pop-up ads, unfamiliar programs or icons on your device, and slow system performance. Malware can also eat up memory and clog hard drive space.
Computer viruses are malware that self-replicate by inserting their code into other programs and files. They can cause damage in various ways, including stealing data, encrypting files, and installing more malware on the device.
A virus can also occupy the device’s processing resources, leaving less power available for other applications and causing the device to slow down. Many types of malware also monitor the device and its users, spying on their browsing habits and sending that information back to attackers.
Viruses can spread through physical and virtual methods, including USB drives, popular collaboration tools, and drive-by downloads.
Symptoms of a virus infection include slower performance, a sudden drop in speed, and rogue processes appearing in Windows Task Manager. Often, viruses also create pop-up ads or redirect browsers to malicious websites. They can also corrupt or delete files on your device, which makes restoring these lost files difficult.
Spyware is software that quietly infiltrates a device to gather data without the user’s permission. Typically, this data is then sent to the attacker. In the most dangerous cases, spyware can be used for identity theft and targeted business attacks.
Adware, Trojans, internet tracking, and system monitors are the four basic types of spyware. The less harmful versions of these programs are designed to gather marketing information, while the more advanced varieties can capture keystrokes, passwords, website visits, and other sensitive data.
A malware infestation could be the reason for a sudden decline in performance on your computer or mobile device. These threats can suck up memory, processor, and other resources, which causes the device to run slowly or experience frequent crashes. You might also see unexplained changes to your device’s settings or search results. Other symptoms include uninvited pop-up ads and suspicious files on your device. If you suspect a problem and want to learn what is malware, consult an IT expert or online tech support service. They can identify the threat type and help you remove it.
Trojans are malware that, like other threats, can severely decrease the functionality of your device and cause you to download even more dangerous programs. They can damage files, redirect internet traffic, monitor your activity, or steal sensitive data.
Unlike viruses and worms, Trojans cannot spread themselves but require that you manually install them. You can inadvertently infect your computer or mobile device by downloading MP3 songs from unsecured websites, playing games that aren’t safe, or clicking on ads that pop up when you are browsing the internet.
While a few Trojans are destructive, most are used to generate profit. One of the most common Trojan programs is called a Remote Access Trojan (RAT), which allows attackers to control compromised machines from anywhere on the internet. It also enables them to execute various commands on the infected computer remotely. Some Trojans also read keystrokes to steal passwords and other personal information. Others, such as the banking Trojan or the Trojan GameThief, target specific financial services or online gaming accounts. Symptoms of infection include poor device performance, programs running that you didn’t initiate, and a sudden uptick in spam and other distractions while using your device.
A horde of infected devices controlled by malware is what we call a botnet. This growing cyber threat is a cybersecurity nightmare because it’s often difficult to detect.
Using internet connectivity, these malware-infected online devices communicate with one another, sending updates and commands back to their hacker or criminal “bot herder” for instructions. This allows them to carry out functions such as phishing attacks, click fraud, and distributed denial-of-service (DDoS) attacks.
Some of the best ways to protect against bots are regularly updating your computer software, scanning files before downloading them, and avoiding suspicious emails from friends and family members. But next-gen security software can also help stop malicious background activity by identifying suspicious programs that consume high amounts of disk resources, for example.
A botnet can contain thousands or even millions of devices that attackers commandeer to relay spam and conduct DDoS attacks and other cyberattacks. But most users must realize it because a typical bot has a small footprint and hides behind legitimate computer tasks.
Rootkits are types of malware that allow thieves to access a computer system’s core. They are used to bypass security software, go undetected by administrators and users, and steal data from the machine.
There are many different types of rootkits. Hardware rootkits take advantage of firmware vulnerabilities in motherboards, network cards, basic input/output systems, and other peripherals to gain control over a device.
Memory rootkits reside in a machine’s RAM and use the computer’s resources to carry out malicious activities in the background. They typically have short lifespans and require additional work to get rid of, but they still pose a threat because they affect your computer’s RAM performance. Kernel mode rootkits operate at the kernel level and can be extremely difficult to detect because they alter existing software. Look out for unauthorized network traffic, unexplained computer slowness, and unresponsive programs as signs of a rootkit attack.