An integrity check is a security control that verifies a file, update, or package has not been changed or damaged. Common methods include cryptographic hashes, digital signatures, and package validation before software is installed or executed.
In cyber security, integrity checks help block tampering and accidental corruption. They are especially important for plugins, patches, and remote management tools, where trusted platforms load code from external sources. If an attacker can replace a package in transit or feed a malicious update into a weak approval flow, the software may install code that looks legitimate but is actually altered. Strong integrity checks reduce that risk by confirming the content matches the expected version and origin. Defenders use them to enforce software trust boundaries, while attackers often try to bypass them by abusing unsigned code, stolen signing keys, or insecure update channels.