Scenario: You're handed a database backup and told to restore it to a server (that's already hosting other databases), but are given no useful information about what the backup contains or whether the source should be trusted.
Question 1: What are the potential implications of restoring a backup that could well be malicious?
Question 2: What can you do to protect your server/the data in other databases from the impact of restoring a potentially-malicious backup?
RESTORE VERIFYONLY would seem to be a good first step. The ultimate answer is probably 'restore the database in a sandbox VM with no access to the outside world', but let's assume that option is off the table. What else should be done in this situation?