Unidentified removable devices, such as USB drives, are a common threat vector for insider threat actors attempting data exfiltration. Insiders can easily use these devices to transfer sensitive data out of the organization undetected, making it one of the most commonly utilized methods for data theft.
Default network device credentials are a security vulnerability but not typically used for data exfiltration.
Spear phishing emails are used for external attacks, not insider data exfiltration.
Impersonation through typosquatting is typically used by external actors for phishing or fraud.