You should avoid early returns whenever possible so it's easier to follow the exit points for a method.  This should be refactored to eliminate this early return.  Including [my earlier comment](https://github.com/rapid7/metasploit-framework/pull/2035/files#r4952154) and eliminating the explicit return, this would be (replace lines 60 through 63):

```ruby
check_code = Exploit::CheckCode::Safe

if shell and shell.body.include?(confirm_string)
  check_code = Exploit::CheckCode::Vulnerable
end

check_code
```