The disgruntled employee insider threat

by Mike Tierney | Jul 17, 2015

Computerworld UK has a great article out on the insider data breach at Morrisons supermarkets in the United Kingdom.

In March 2014 the theft and leaking of payroll data on 100,000 employees for Morrisons was made public. The data taken included back account details, and was published online and sent via disc to at least one newspaper.

At trial, the prosecution has said that the employee "decided to publish the database containing employee names, addresses, bank account numbers and national insurance numbers in revenge for being incorrectly disciplined for receiving packages at the company's head office."

The alleged leaker wrote in a resignation letter days before the incident occurred "I have almost as little concern for the company as it does for me" according to the prosecution.

This is a textbook disgruntled employee insider threat case study. An employee, one who by nature of their position has authorized access to sensitive data and systems, perceived (possibly rightly, possibly not) that the organization wronged him, and sought retribution. Estimates for the amount Morrisons has spent on remediation seem to be around 2 million pounds (a bit over $3.1M at todays conversion rate).

The Computerworld UK article asks how someone was able to steal the entire employee database, and we may learn more details around that as the case progresses. As with all insider attacks, the unique challenge making sure authorized access is used for its intended purpose exists. With insider threats, there must be a dedicated detection program in place - one that combines technology, people, and process.

Based on what we have learned to date, it appears that tighter coordination between Human Resources and Information Security would have helped here. Had HR communicate to InfoSec that elevated risk existed involving the disciplined employee (which can be done without violating employee privacy by revealing the reasons why if a simple process is in place), InfoSec could have reacted to that by increasing inspection of the activity of this employee. Employee monitoring solutions make that job easier for InfoSec than attempting to do it using tools that are not purpose built for the task.

This is a topic we have been talking about at SpectorSoft for some time. We have a whitepaper on the very subject of preventing employee risk from becoming insider threat, and a webinar on the topic as well. I encourage anyone who is concerned this type of situation could happen to them to access these free resources.