Adversaries may erase the contents of storage devices on specific systems or in large numbers in a network to interrupt availability to system and network resources.
Adversaries may partially or completely overwrite the contents of a storage device rendering the data irrecoverable through the storage interface.(Citation: Novetta Blockbuster)(Citation: Novetta Blockbuster Destructive Malware)(Citation: DOJ Lazarus Sony 2018) Instead of wiping specific disk structures or files, adversaries with destructive intent may wipe arbitrary portions of disk content. To wipe disk content, adversaries may acquire direct access to the hard drive in order to overwrite arbitrarily sized portions of disk with random data.(Citation: Novetta Blockbuster Destructive Malware) Adversaries have also been observed leveraging third-party drivers like RawDisk to directly access disk content.(Citation: Novetta Blockbuster)(Citation: Novetta Blockbuster Destructive Malware) This behavior is distinct from Data Destruction because sections of the disk are erased instead of individual files.
To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware used for wiping disk content may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.(Citation: Novetta Blockbuster Destructive Malware)
Detection Strategy for Disk Content Wipe via Direct Access and Overwrite
Data Backup: Data Backup involves taking and securely storing backups of data from end-user systems and critical servers. It ensures that data remains available in the event of system compromise, ransomware attacks, or other disruptions. Backup processes should include hardening backup systems, implementing secure storage solutions, and keeping backups isolated from the corporate network to prevent compromise during active incidents. This mitigation can be implemented through the following measures:
Regular Backup Scheduling:
Immutable Backups:
Backup Encryption:
Offsite Backup Storage:
Backup Testing: