Thursday, July 11, 2019

Control of Privileged Insiders

On April 23, 2019 the FBI published a Private Industry Notification (20190423-001).  The document was distributed as a pdf only by e-mail.  While marked “TLP-White,” “may be distributed without restriction," I could not find it on the web.

The summary read:

The FBI continues to observe U.S. businesses’ reporting significant losses caused by cyber insider threat actors.  These cases often involve former or disgruntled employees exploiting their enhanced privileges—such as unfettered access to company networks and software, remote login credentials, and administrative permissions— to harm companies. Cyber insider threat actors most often are motivated by revenge, but they also conduct attacks to profit financially from stolen information, gain a competitive edge at a new company, engage in extortion, or commit fraud through unauthorized sales and purchases.

I recommend it to the reader.  (Since I cannot find it on the web, here is a link to a private copy.)

There are two kinds of insider risk, accidental and intentional, and three threat sources, benign, dishonest, and disgruntled employees.  Note that insider threat rate is much lower than the outsider threat but the consequences, and therefore risk, may be much greater.  Outsiders damage the brand while insiders may bring down the business.

Not only is employee error by otherwise well motivated and intended employees perhaps the biggest source of losses ("The dummies have it, hands down, now and forever."  --Robert H. Courtney)  but it contributes to the success of attacks by outsiders. (Think “phishing” and other forms of duping.)  Undetected errors may result in employee temptation and fraud.  The employee makes an error and no one notices.  She repeats and still no one notices.  She finally concludes that she could do it in her own favor and still no one would notice.   We distinguish between dishonest employees, who want to keep their activities secret, and disgruntled employees who want you to know that you have been injured.  

Management supervision is the most effective of all insider controls.  Effective supervision usually requires that the supervisor could do, or at least appreciate, the job being supervised.  This control often breaks down for privileged IT jobs.  The more sensitive or unique the task to be supervised, the more narrow should be the span of control.  While one might be able to supervise a dozen tellers or coders, one might supervise no more than five or six loan officers, system designers, or privileged administrators.  

The limitation of supervision is cost; while it is effective, it is also expensive.  Therefore, other more efficient and complimentary controls are often substituted for all or part supervision.  These might include background checks, training, division of responsibility and privileges (so-called multi-party controls), cross training, job rotation, measurement, mandatory vacations, audit trails and audits, recognition, compensation, and complete and timely separation.  

I had been writing and talking on this subject for a few years before I added “please and thank you” to my list of controls.  While equitable compensation is a powerful control, no amount of it can compensate for inadequate recognition.  Many dishonest and most disgruntled employees feel that their contribution to the enterprise has not been appreciated.  Please and thank you go a long way toward maintaining necessary morale.  

The FBI notification gives special attention to IT personnel and, especially, privileged users such as system administrators.  Management often focuses on lower level employees, like tellers or clerks, doing routine tasks.  Where these engage in fraud they get little and are caught early.  It is professionals, managers, and executives who bring down the business.

It is ironic that these highly privileged actors are often inadequately supervised, under paid, and unaccountable.  We caution against the sharing of user IDs and passwords, but it is privileged IDs and passwords that are most likely to be shared.  Many administrators have so much privilege that they cannot be held accountable, can escalate their privileges, and the privileges, once granted, cannot be effectively withdrawn.  Think about the privileges that Edward Snowden had to have accumulated to gain access to all the information that he exfiltrated.  

One should not grant privileges that one cannot withdraw.  Therefore, privileged users should be required to use hardware token based strong authentication.  One should not grant privileges without accountability for their use.  Therefore, when there is more than one privileged user, i.e., in most large enterprises, Privileged Access Management (PAM) controls should be in place.  These controls will be covered in a later post.

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