Who Is Phoning Home on Your Firm's Dime?

ExtraHop customers in 2018 and the first weeks of 2019 took a look at some third-party supplied enterprise software's behavior and were not pleased when it would, unannounced, call home for its creators. ExtraHop took a further look and wrote a report about it. In its report, ExtraHop develops four case studies of how this sort of thing happens.

The first case study involves a financial services provider. The ExtraHop trainer that was at the organization noticed that domain controllers were shipping data to a public cloud instance. The customer's immediate reaction was said to be "that's not possible." However, domain controllers were definitely sending SSL traffic outbound to 50 different public cloud endpoints.

A glance at the underlying certificate for the client/server session revealed another well-known vendor was phoning data home to a cloud storage instance in vendor-owned IP space. The financial services company had evaluated the vendor's product months earlier but didn't buy it. All vendor connections were supposed to have terminated when the proof of concept (POC) ended, but it's evident that outbound traffic had continued for at least two months. The problem had a root cause in the vendor's actions, not the service provider.

A hospital located in the Western United States had the same sort of problem. They were trying to install a a medical device management product that manages phones and tablets when they found out the product was opening encrypted SSL:443 connections to vendor-owned cloud storage. But because the hospital was subject to HIPAA regulations an incident such as this (an unknown data leak of unknown duration that could involve personally identifiable information) typically requires significant documentation, as well as incident response and cleanup.

A large multinational food services company realized that approximately every 30 minutes, a network-connected device was sending UDP traffic out to a known bad IP address. The device turned out to be a Chinese-manufactured security camera. It was probably independently installed by an employee at their office for perceived personal security purposes. It goes to show how a well-known consumer brand can expose an enterprise's network to risk.

Working with a large financial services institution in the US Midwest, ExtraHop found a large volume of outbound traffic headed from the customer's US datacenter to the United Kingdom. It turned out to be due to a security technology vendor that was also in a POC in the same time frame.The customer was unaware that any data was leaving their environment. Because the data was crossing geographic and political boundaries, it could be prosecuted if not done properly under data compliance regimes like the Gramm-Leach-Bliley Act (GLBA) and GDPR.

The point of all this is simple, really. An organization's daily business may expose it to security risks that it is totally unaware of. Those risks may result from exfiltration of data, or other data transmissions that have been established without an organization's knowledge. It's an unknown that has to be trapped by an organization through review of what is happening, not what the organization wants to be happening.

So, monitor all vendor activity even if they are supposed to be off the network. Keep looking for rogue data transmissions, regardless of who is making them. Above all, create a security regimen that will be deep enough to be effective but still flexible enough to be routinely used.

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.