Offline backup
Also called: offline backups · air-gapped backup
A backup kept disconnected from the corporate network and live systems, such as rotated tapes or drives, and connected only while backing up or restoring. Ransomware encrypts or deletes every backup it can reach, so an always-connected NAS or a synced cloud folder does not count. Keep offline copies current and test restoring from them.
Further reading: www.ncsc.gov.uk
From the Security Academy
Backup Strategy: the 3-2-1 Rule, Immutable Copies and Restore Drills
Backups are the last line of defence against ransomware only if they survive and restore. Covers 3-2-1, offline and immutable copies, RPO/RTO and drills.
8 min read ·
Advisories that mention this term
Auto Parts Manufacturer Orange Electronic Reports Ransomware Attack on Local Network Storage Devices
On October 28, Orange Electronic issued a material information filing on MOPS stating that some of its local area network storage devices had been hit by a ransomware attack, and its cybersecurity team immediately activated defense mechanisms and network isolation .
CISA and FBI warn SafePay ransomware gang has hit about 600 organizations
CISA, the FBI, the US Secret Service and international partners released a joint advisory warning that SafePay is one of the most active ransomware groups of 2026, impacting about 600 victims across the Americas, Europe and Australia .
China's CVERC warns new "Sorry" ransomware exploits cPanel flaw CVE-2026-41940 against Linux servers
CVERC warned of multiple attacks in China by "Sorry", a ransomware family that emerged in 2026 and mainly targets internet-exposed Linux web servers .