Device compromise is unauthorized control or influence over a computer, phone, or workstation. An attacker may gain enough access to run code, change settings, steal data, monitor activity, or use the device as a foothold into other accounts and systems. The compromise can come from malware, stolen credentials, malicious links, unsafe downloads, or social engineering that convinces a user to approve access.
In cyber security, device compromise matters because one infected or hijacked endpoint can expose passwords, session tokens, documents, and connected services. Attackers often use the compromised device to move laterally, reset accounts, or launch further fraud. Defenders reduce risk with phishing resistance, patching, endpoint protection, least privilege, device monitoring, and strong identity controls such as MFA and separate work and personal accounts.