If you get the error message “sql_exec_internal: sqlite3_step failed: database disk image is malformed” preventing you from starting or logging into OpenVAS, this article should help. The issue may have been caused by an unexpected power-down, but whatever caused it, the DB is corrupt. Not that this is the same DB that stores your OpenVAS data including login information.
Warning: This process results in loss of settings and data. Backup first.
Restore this file from backups:
/var/lib/gvm/gvmd/gvmd.db
Or move it aside and re-run the installation program. Warning, this will result in loss of OpenVAS information.
openvas-setup