1

I have been given a situation (see below),The question i need to answer to complete the task is: What is the ALE for phishing emails for the company, in pounds; e.g. 203,760? When i multiply the answers i have ARO * AV * EF = 38631600. This answer comes back as incorrect and i am struggling finding the correct:

Asset Value - AV (I get £1575000 - £225*7000)

Exposure Factor - EF (I get 0.01 - 225 is 0.01% of 1575000)

Annualised Rate of Occurrence - ARO

80*7000*365 = 204400000

204400000 * 0.2% = 408800

408800 * 30% = 122640

122640 * 2% = 2452.8

Phishing is of major concern to an organisation, so they have begun to monitor how big a risk it is posing. On average, 80 phishing emails are sent to everyone in the company per day. The company email filters stop 99.8% of these getting through. Of the emails that do get through, 30% of employees click on the link. Out of those employees, 2% expose their company login details to the phishing website. For every set of company login details that are exposed to the hackers, the company has found that it costs them £225. The company has 7,000 employees.

Luke Costello-Watkins
  • 11
  • 4
  • Your ARO looks fine. And I would probably do the calculations the same way, but in practice, I would want to sit down with stakeholders to understand the numbers. I wonder about your asset value. What happens if you use £225 in your calcuations and enter that result the online tool? – schroeder Jan 29 '19 at 09:48
  • i have came to the same answer too Luke and it comes back as incorrect.Let me know if you have any luck with it. Thanks Davy – Davy Strain Jan 29 '19 at 09:01
  • Thanks Davy that has got me out of days of frustration – Luke Costello-Watkins Jan 30 '19 at 09:22

1 Answers1

0

Thanks goes to Davy Strain for providing this answer.

The SLE is given in the data so no need to work out the AV/EF, i was overthinking the data.

SLE = 225

Annualised Rate of Occurrence - ARO

80*7000*365 = 204400000

204400000 * 0.2% = 408800

408800 * 30% = 122640

122640 * 2% = 2452.8

ALE = ARO 2452.8 * SLE 225

=>ALE = 551,880

Luke Costello-Watkins
  • 11
  • 4