A program that infects other ones, by adding its code to them in order to gain control when infected files are run. This simple definition allows identifying the main action performed by any virus: infection.

An infrastructure of cloud services that provides access to the Kaspersky Lab database with constantly updated information about the reputation of files, web resources, and software. Kaspersky Security Network ensures faster responses by Kaspersky Lab applications to threats, improves the performance of some protection components, and reduces the likelihood of false positives.

A technology for detecting threats about which information has not yet been added to Kaspersky Lab databases. The heuristic analyzer detects objects whose behavior in the operating system may pose a security threat. Objects detected by the heuristic analyzer are considered to be probably infected. For example, an object may be considered probably infected if it contains sequences of commands that are typical of malicious objects (open file, write to file).

Databases that contain information about computer security threats known to Kaspersky Lab as of when the anti-virus databases are released. Entries in anti-virus databases allow malicious code to be detected in scanned objects. Anti-virus databases are created and regularly updated by Kaspersky Lab specialists.