A report from Tenable Network Security identifies that blind spots “can increase legal risk because information retention policies designed to limit legal liability are very unlikely to be applied to electronically stored information (ESI) contained on unauthorized cloud, mobile and virtual assets.” Tenable Network Security’s April 15, 2015 report entitled “Eliminating Cybersecurity Blind Spots” includes these three continuous activities:
- Passive Network
- Monitoring Active Scanning
- Event Log Analysis
Here are more details on Passive Network Monitoring from the Report which includes detection of access cloud connections:
Passive network monitoring continuously analyzes network traffic at the packet layer to build a model of active devices and applications on the network. Because passive detection operates 24/7, it will detect transitory assets that may only be occasionally and briefly connected to the network and can send alerts when new assets are detected.
Passive monitoring can frequently determine a device’s operating system and version using OS fingerprinting techniques that can also identify protocols and protocol versions. More importantly, passive monitoring can identify client applications used on the network, such as email clients, web browsers and chat programs. It can also detect FTP peer-to-peer file sharing, and connections to cloud services such as DropBox, YouSendIt and Box.net. As described earlier, when protected/proprietary data is sent to unsanctioned cloud applications, organizations are frequently exposed to significant hidden risk. Sophisticated passive monitoring tools have the ability to examine unencrypted data sent to the cloud to determine if it contains protected/proprietary data that should not leave the premises.
Advanced passive monitoring tools can associate discovered operating systems, protocols and applications with known vulnerabilities, enabling organizations to prioritize remediation as vulnerabilities are discovered. These tools can also detect when systems are compromised based on application intrusion detection.
Advantages of passive network monitoring are: it identifies transient systems that may only be on the network a brief time; it does not perturb the network or devices on the network; it has visibility of Internet and cloud services being accessed from systems on the network; and it can identify vulnerabilities in real-time, 24/7, to eliminate gaps between active scans (described below) and accelerate threat remediation. The shortcoming of passive network monitoring is that passive detection sensors must be strategically deployed throughout the network so they can monitor all desired traffic, and if the network is reconfigured without reconfiguring or deploying additional passive sensors, devices and applications may not be detected.
All business should heed this advice about protecting the blind spots.