Explanation
AWS Classic resources run in a shared environment with infrastructure owned by other AWS customers. You should run resources in a VPC instead.
Insecure Example
The following example will fail the AWS003 check.
resource "aws_db_security_group" "bad_example" {
# ...
}Secure Example
The following example will pass the AWS003 check.
resource "aws_security_group" "good_example" {
# ...
}