If you’re looking for antivirus protection you’re searching for software which can detect and block malware, which are programs designed to cause damage to laptops and computers as well as steal data or corrupt systems. Malware can be triggered by malicious emails and attachments or embedded in questionable USB drives, or even in online advertisements.

The best antivirus programs are able to identify and block cyber-attacks. They also provide top customer service. Certain programs are back by a money-back guarantee.

The majority of the antivirus software we tested for this report had an array of options to detect or prevent infections. Heuristic and signature detection compares incoming programs or files with known malware signatures. Heuristics also examines program behavior, looking for anomalies or unusual behavior.

Many programs also include a firewall, which monitors activity and blocks certain ports to stop attacks. Some also include ransomware protection which locks data to ensure that you’ll be required pay a fee to decrypt it. Some also offer web security via browser plugins or extensions, which block malicious websites or prevent you from accidentally handing over personal information to nefarious actors.

A lot of these applications rely on cloud-based authentication of URLs, data files, and other data. They upload a list with official statement all the installed and running applications, their signatures and metadata to the cloud to be compared against the company’s database. The companies differ on how they disclose this and whether they allow you to remove yourself from.