Adversaries may corrupt or wipe the disk data structures on a hard drive necessary to boot a system; targeting specific critical systems or in large numbers in a network to interrupt availability to system and network resources. Adversaries may attempt to render the system unable to boot by overwriting critical data located in structures such as the master boot record (MBR) or partition table.(Citation: Symantec Shamoon 2012)(Citation: FireEye Shamoon Nov 2016)(Citation: Palo Alto Shamoon Nov 2016)(Citation: Kaspersky StoneDrill 2017)(Citation: Unit 42 Shamoon3 2018) The data contained in disk structures may include the initial executable code for loading an operating system or the location of the file system partitions on disk. If this information is not present, the computer will not be able to load an operating system during the boot process, leaving the computer unavailable. Disk Structure Wipe may be performed in isolation, or along with Disk Content Wipe if all sectors of a disk are wiped. On a network devices, adversaries may reformat the file system using Network Device CLI commands such as `format`.(Citation: format_cmd_cisco) To maximize impact on the target organization, malware designed for destroying disk structures may have worm-like features to propagate across a network by leveraging other techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.(Citation: Symantec Shamoon 2012)(Citation: FireEye Shamoon Nov 2016)(Citation: Palo Alto Shamoon Nov 2016)(Citation: Kaspersky StoneDrill 2017)
Processes attempting raw disk access to overwrite sensitive structures such as the MBR or partition table using \\.\PhysicalDrive notation. Detection relies on correlating process creation, privilege escalation, and raw sector writes in Sysmon and Security logs.
Execution of utilities (dd, hdparm, sgdisk) or custom binaries attempting to overwrite disk boot structures (/dev/sda MBR sector or partition tables). Detection correlates shell execution with syscalls writing to sector 0 or disk metadata blocks.
Abnormal invocation of diskutil or asr that modifies partition tables or initializes raw devices. Monitor for IOKit system calls targeting disk headers or EFI boot sectors, correlated with elevated privileges.