With phishing campaigns now the #1 cause of successful breaches, it’s no wonder more and more businesses are investing in phish simulations and cybersecurity awareness programs. These programs are designed to strengthen the biggest vulnerability every business has and that can’t be fixed  through technological means: the human factor. One common misconception that may employers have, however, is that these programs should result in a systematic reduction of phish clicks over time. After all, what is the point of investing in phish simulations if your employees aren’t clicking on less phish? Well, a recent report from The National Institute of Standards and Technology actually makes the opposite argument. Phish come in all shapes and sizes; some are easy to catch while others are far more cunning. So, if your awareness program only focuses on phish that are easy to spot or are contextually irrelevant to the business, then a low phish click rate could lead to a false sense of of security, leaving employee’s unprepared for more crafty phishing campaigns. It’s therefore important that phish simulations present a range of difficulty, and that’s where the phish scale come in.

Weighing Your Phish

If phish simulations vary the difficulty of their phish, then employers should expect their phish click rates to vary as well. The problem is that this makes it hard to measure the effectiveness of the training. NIST therefore introduced the phish scale as a way to rate the difficulty of any given phish and weigh that difficulty when reporting the results of phish simulations. The scale focuses on two main factors:

#1 Cues

The first factor included in the phish scale is the number of “cues” contained in a phish. A cue is anything within the email that one can look for to determine if it is real of not. Cues include anything from technical indicators, such as suspicious attachments or an email address that is different from the sender display name, to the type of content the email uses, such as an overly urgent tone or spelling and grammar mistakes. The idea is that the less cues a phish contains, the more difficult it will be to spot.

#2 Premise Alignment

The second factor in the phish scale is also the one that has a stronger influence on the difficulty of a phish. Essentially, premise alignment has to do with how accurately the content of the email aligns with what an employee expects or is used to seeing in their inbox. If a phish containing a fake unpaid invoice is sent to an employee who does data entry, for example, that employee is more likely to spot it than someone in accounting. Alternatively, a phish targeting the education sector is not going to be very successful if it is sent to a marketing firm. In general, the more a phish fits the context of a business and the employee’s role, the harder it will be to detect.

Managing Risk and Preparing for the Future

The importance of the phish scale is more than just helping businesses understand why phish click rates will vary. Instead, understanding how the difficulty of a phish effects factors such as response times and report rates will deepen the reporting of phish simulations, and ultimately give organizations a more accurate view of their phish risk. In turn, this will also influence an organization’s broader security risk profile and strengthen their ability to respond to those risks.

The phish scale can also play an important role in the evolving landscape of social engineering attacks. As email filtering systems become more advanced, phishing attacks may lessen over time. But that will only lead to new forms of social engineering across different platforms. NIST therefore hopes that the work done with the phish scale can also help manage responses to these threats as they emerge.