Customer Zero: a case study

Netskope

Being CISO for a security technology vendor can be an interesting position. My job combines the usual CISO responsibilities alongside daily self and industry analysis as I support our own product teams to continually improve their understanding of, and support for my industry peers.  In this role, I thought it would be interesting to share a recent experience of a security threat originating from one of our enterprise software cloud service providers.

The identification

One of the many benefits of being a security company is that the employees are generally savvy about spotting security threats, so the identification of this event came in the form of a morning phone call, alerting me that one of the cloud services our sales team uses was experiencing a DNS redirection issue.  In this example, automatically redirecting to a uncategorised site.  Had I not had that call it would only have taken a few more users logging in and taking an action including an actual attempt to download the malicious flash player binary the page was serving for our threat detection engine to trigger and our machine learning anomaly detection (MLAD) algorithms to report the incident , but as it was, I got a head start on the machines (thanks Andy!)

My process

My first step was to block the dormant redirect site with our Netskope for Web gateway, so that I could be confident it was no longer a threat.  Having taken that simple step, I needed to start on a more forensic assessment of exactly what the threat had been. 

Our CASB enables me to monitor all of the cloud services we use (Netskope CASB has a database of 28,500+ cloud apps), so I could instantly check to see who had recently used the service in question, and what data movements there had been (i.e. had any sensitive data been compromised).  While no data had been compromised,  I was particularly grateful for the CASB at this point because (as is common for cloud services) the affected service requires a number of exceptions to be added to more traditional secure web gateways and analysing logs with exceptions is not an efficient method to triage activity .  Without the CASB, I would not have had any detailed insight on the user, application and data interactions and would have had to assume the worst case scenario , that the whole organisation may have been affected.

By collating information from both the vendor concerned (who, when asked, provided details of the time period of the DNS issue) and our own analytics engine, my analysis identified 24 employees who had used the service during the compromised period.   The CASB told me exactly who they were, so I was able to perform targeted retrospective endpoint scans to look for (and eliminate) any malicious payloads that may have made it onto our systems. For this, Netskope’s product integrates directly with many endpoint technology providers allowing our security teams to initiate these scans directly through the Netskope console for the 24 employees potentially exposed.

Happily ever after

The dwell time on this threat was about 10 minutes, which meant that no major damage was done, but the risk was acute.  I was helped by proactive employees reporting of the issue, which reiterates the importance of employee threat education.

Conclusions

I often consider myself ‘customer zero’ for Netskope technology.  Everything we build gets its first real-world installation on our systems, and as such I am probably the most awkward customer we have. As CISO  I am, after all, responsible for the effectiveness of our systems and processes.

For me, the integration of the secure web gateway and cloud access security broker is incredibly useful, but it is definitely the cloud security capabilities that leads our security team. With the web exceptions and ‘direct-to-net’ loopholes needed to run a modern digital workplace, I see a web gateway as a sledgehammer tool.  Sometimes you need to be aggressive and unequivocally block a site and a web gateway is just the tool for the job. But more often nowadays I need much more information and context for a more nuanced approach to security, and it is the CASB that gives me that.